Sharks are not known for being good at running in running wheels. Or hopping from one perch to the other in a birdcage. Which is why, unlike hamsters or sparrows, sharks were never a very popular laboratory model for circadian research.
The study of fish came late into the field of chronobiology due to technical difficulties of monitoring rhythms, at the time when comparative tradition was starting to make way to the more focused approach on choice model organisms – in this case, the zebrafish.
But the comparative tradition was always very strong in the field. Reading the old papers (especially review papers and loooong theoretical papers) by the pioneers like Jurgen Asschoff and Colin Pittendrigh, it seems like researchers at the time were just going around and saying “let me try this species…and this one…and this one…”. And there were good reasons for this early approach. At the time, it was not yet known how widespread circadian rhythms were – it is this early research that showed they are ubiqutous in all organisms that live at or close to the surface of the earth or ocean.
Another reason for such broad approach to testing many species was to find generalities – the empirical generalizations (e.g,. the Aschoff’s Rules) that allowed the field to get established, and that provided a template for the entire research program, including refining the proper experimental designs.
Finally, this was also a fishing expedition (no pun intended…oh, well, OK, intended) for the best model organisms on which to focus more energies – organisms that can be studied in great detail in both field and lab, that are easy to find, breed, care for, house and handle, and organisms in which circadian rhythms are clear, robust, and are easy to monitor with relatively cheap and simple equipment. Thus hamsters, cockroaches, and sparrows, green anoles and Japanese quail. Later, with molecular discoveries, organisms with better tools for genetic manipulation, even though perhaps not as good as circadian models, took precedence – the fruit fly, mouse, zebrafish and the like.
But it’s not that sharks were never looked at before. They may not run in wheels, but researchers can be creative and monitor the rhythms nonetheless.
Horn Shark and Swell Shark
The Nelson and Johnson 1970 paper appears to be the very first systematic study of daily rhythms in sharks. They cite a number of previous non-systematic observations in the field, all suggesting that many shark species are nocturnal (night-active). They combined field and lab studies in two species (horn shark Heterodontus francisci and the swell shark Cephaloscyllium ventriosum).
Pattern of activity of bottom-dwelling sharks in the field. From Nelson and Johnson 1970.
In the field, they dove at different times of day and night, counted and observed the sharks, and rated their activity levels. Both species were exclusively nocturnal, barely making any movements at all throughout the day, while actively swimming at night.
In the lab, they placed sharks in small pools, each pool in a light-tight enclosure. They controlled lighting regimes (e.g., constant dark, constant light, or various light-dark cycles) and they monitored the activity with a nifty sensor – a set of six steel rods in each pool, each rod hanging from above all the way to the bottom of the water. Whenever a fish pushed one of the rods (and they did not observe any avoidance), the rod would move and momentarily close an electrical circuit. This would be recorded as a dash line on long paper rolls by an Esterline-Angus recorder.
Afterward, they would take those paper rolls out, cut them (by hand) into strips, glue the strips (by hand) onto large pieces of cardboard, do the measurements and calculations (by hand, using rulers and compasses), and photograph the best records for publication. Yes, very manual work! In this day of computers, it’s pretty easy to just click. Our PI used to sometimes take us grad students to a back room to show us the old equipment and to describe the process, just so we would appreciate how easy we have it now.
Actograph of the Swell shark in different light conditions. From Nelson and Johnson 1970.
What they found is that the two species are quite different. The Horn shark readily entrained to the light-dark cycles (both 24-hour and 25-hour cycles), starting activity as soon as the lights go off, and ceasing activity the moment the light come back on. They kept swimming all the time both in constant darkness and in constant light. This suggests that their behavior is triggered directly by environmental light and not driven by an internal clock.
On the other hand, the Swell sharks showed circadian rhythms – they alternated between active and inactive periods in constant light and in constant darkness. In light-dark cycles of both durations, they showed a little bit of anticipation, starting their activity a few minutes before lights-off. This suggests that the daily alteration of behavior is driven by an internal circadian clock.
In a later study (Finstad and Nelson 1975), they changed the intensity of light of the experiment, and this time Horn sharks also exhibited internally generated circadian rhythms.
Daily rhythm in the dogfish shark. From Casterlin and Reynolds 1979.
In 1979, Casterlin and Reynolds tried a different experimental setup and a different species – smooth dogfish shark, Mustelus canis. In their setup, as sharks swim through a series of chambers they break photocell-monitored light beams. Instead of simple light-dark cycles, they used light-dusk-dark-dawn cycles in which dawn and dusk light was dim, while daytime light was bright. Again, most of the activity was observed during the night:
In 1988, Nixon and Gruber took a bunch of Lemon sharks (Negaprion brevirostris) and placed them in a complex setup in order to simultaneously monitor both locomotor activity (that is: swimming around and around in circles) and the metabolic rate (oxygen consumption):
The lemon shark setup. From Nixon and Gruber 1988.
Daily rhythms of activity (top) and metabolic rate (bottom) in the Lemon shark. From Nixon and Gruber 1988.
The sharks were only tested in light-dark cycles, which is not a proper test for the existence of the circadian clock, but the data were strikingly “clean”. While behavior can be strongly affected by direct influence from the environment (e.g., sudden lights-on), it is harder to explain changes in metabolic rate purely behaviorally, suggesting that an internal clock is likely driving the day-night differences in metabolism.
Megamouth shark daily dives. From Nelson et al. 1997.
This big guy is hard to find. The subject of this paper was only the sixth individual known to science. It was caught, they scrambled for about a day to get all the gear in place, attached satellite telemetry radiotransmitters, and let the animal lose to swim. What they saw was a distinct pattern of diving deeper before the sunrise, and rising up closer to the surface before sundown. While nothing can be said about circadian regulation, as the pattern could just be the animal following light clues or vertical migration of its plankton food, it is nonetheless a very cool study.
It is interesting that a number of senior researchers, as they come close to retirement and are not in the rat-race for grant funding any more, abandon the standard lab models and go back to the old comparative tradition, picking unlikely species (from chipmunks to Monarch butterflies) and moving out of the lab back into the field. It’s definitely more fun to do!
One of them decided to shift his focus to juvenile hammerhead sharks. Unfortunately, Milton H. Stetson suddenly died in 2002, and I could only find one publication from that work (Okimoto and Stetson 1995), which I cannot read as it was published in a conference proceedings (if anyone can scan a copy and send me, I’ll be grateful):
Nonetheless, this paper was cited in several other places, and if they cited it correctly, what Okimoto and Stetson found was that the pineal glands of these sharks (and later the same also found in dogfish shark Squalus acanthias) does not show cycles of melatonin synthesis and release in constant light conditions (it does in light-dark cycles). This does not necessarily mean that there is no clock in the pineal, or that there is not rhythmic production of melatonin, as later work in our lab showed that culture medium can have a dramatic effect.
Combined 206 daily records of a whale shark dives. From Graham, Roberts and Smith 2006
In Graham, Roberts and Smith 2006, nine whale sharks were tagged with archival satellite tags which provided data on water temperature, illumination and depth. What they found are three distinct types of rhythms: ultradian (short), circadian (about a day) and infradian (long) cycles.
The short cycle was about 45 minutes long, essentially the sharks swimming up an down underneath the surface, not really diving very deep.
One day record of a whale shark diving activity. From Graham, Roberts and Smith 2006
The long cycle was a 29-day cycle, likely not generated from within the nervous system of the shark, but rather the animals following the snapper spawning events which are modulated by the moon phases.
The daily cycle was that of deep dives. The sharks made very deep dives – sometimes over a kilometer down – only during the day. Again, nothing in this experimental protocol can distinguish between internally generated rhythms and behaviors directly induced by the environment, e.g., light intensity, vertical migrations of prey, etc.
And yes, this is it, that’s all. Not much work on sharks done, for obvious reasons – they don’t do well in running wheels.
Casterlin, Martha E., and William W. Reynolds. Diel activity patterns of the smooth dogfish shark, Mustelus canis. Bulletin of Marine Science 29.3 (1979): 440-442.
Finstad WO, Nelson DR. Circadian activity rhythm in the horn shark, Heterodontus francisci: effect of light intensity. Bull. S. Calif. Acad. Sci, 1975
Graham, Rachel T., Callum M. Roberts, and James CR Smart. Diving behaviour of whale sharks in relation to a predictable food pulse. Journal of the Royal Society Interface 3.6 (2006): 109-116.
Nelson, Donald R., and Richard H. Johnson. Diel activity rhythms in the nocturnal, bottom-dwelling sharks, Heterodontus francisci and Cephaloscyllium ventriosum. Copeia (1970): 732-739.
Nelson, Donald R., et al. An acoustic tracking of a megamouth shark, Megachasma pelagios: a crepuscular vertical migrator. Environmental Biology of Fishes 49.4 (1997): 389-399.
Nixon, Asa J., and Samuel H. Gruber. Diel metabolic and activity patterns of the lemon shark (Negaprion brevirostris). Journal of experimental Zoology 248.1 (1988): 1-6.
Okimoto, D. K., and M. H. Stetson. Effect of light on melatonin secretion in vitro from the pineal of the hammerhead shark, Sphyrna lewini. Proceedings of the Fifth International Symposium on Reproductive Physiology of Fish, The University of Texas at Austin. 1995.
Mars has two moons - Phobos and Deimos. Here we see Phobos passing in front of the sun, as seen from the surface of Mars. How would having two moons with different phases affect behavior of Martians?
Scientific papers usually don’t faithfully convey exactly how the researchers came up with the idea, or the chronological order in which the investigation proceeded. And there is a good reason for that – papers need to be standardized so other scientists can easily read them, understand them, replicate them and use them to perform further research.
But sometimes, a paper is honest about the process. It is wonderful – and shows that scientists are human, with a great sense of humor – when #OverlyHonestMethods sneak into the text of a scientific paper, surprising and rewarding the careful reader with an ‘easter egg’.
One such paper – on the effects of moon phase of sleep quality – just came out in Current Biology.
The first thing I noticed was that the data were collected in 2000-2003. Why did it take a decade to publish? Was it just sitting on a back burner of a PI for years after the student left the lab? Did it have to go through many rounds of peer review in several journals until it finally managed to get published? None of those reasons, actually! See for yourself:
We just thought of it after a drink in a local bar one evening at full moon, years after the study was completed.
And that is where we encounter yet another effect of the full moon (in synergy with ethanol) on human behavior, at least on WEIRD populations, such as scientists!
But jokes aside, this is also a great example of a paper that usefully re-visits and re-analyzes old data sets. Of course, the authors emphasize the positives of this post hoc approach – nobody at the time of the study could possibly know that the data would be analyzed in this way, so there were no possible subconscious psychological effects – it was a truly triple-blind study:
Thus, the aim of exploring the influence of different lunar phases on sleep regulation was never a priori hypothesized, nor was it mentioned to the participants, technicians, and other people involved in the study.
On the other hand, a study specifically designed to test for moon-phase effects on sleep quality would have been designed differently to ensure it has just the right controls and that maximum information can be derived from the data.
Research in chronobiology is frustratingly slow. In circadian research, each day is just one data point, so each study has to keep subjects in isolation for many days. In the study of lunar rhythms, each month is a data point and the subjects need to be kept in isolation for many months.
To determine if a rhythm is generated by an internal timer (daily or monthly) as opposed to being a direct behavioral response to environmental cycles requires a whole battery of tests, which are hard and time-consuming enough in circadian research, and twenty eight times more so in circalunar rhythm research
Back in the 1960s, it was possible to keep (well compensated) human subjects in isolation rooms for long periods of time (see pioneering research by Wever and Aschoff in the underground bunker in Andechs, Germany). Likewise, animal subjects can be kept and monitored in isolation chambers for long periods of time.
As lunar rhythms are more “messy” than daily rhythms, more data over more time are necessary for the robust statistical analysis. And, due to ethics creep, it is not certain that either animal or human studies of such scope can be approved and performed any more. So, one has to be creative and get quality information out of imperfect experimental protocols (just like we cannot wait to observe multiple cycles of 17-year cicadas, but have to invent creative, short-term approaches instead).
But this time, the researchers were just lucky! Their data-set came from an old experiment which was designed well enough for this new purpose. The key is they had LOTS of data. Their subjects came in to the sleep lab many times and a number of different parameters were measured. Ideally, each subject would stay in the lab for a few months instead of just four days at a time. But having such a huge data set allowed them to weave together a patchwork of fragmented data into a large, trustworthy whole. Each first night of the test was eliminated from the data due to potential influence of the previous day (and the so-called “weekend effect”, as people tend to change sleep times on their days off). Each phase of the moon was covered by multiple subjects multiple times. So they could employ powerful statistics to tease out the effects of the moon phase on various parameters of sleep quality.
And they found some interesting stuff! My colleague Dina Fine Maron has covered the paper in greater detail here. In short, human subjects with no access to information about moon phase, or any ability to perceive the moon itself or its light intensity, nonetheless slept about 20 minutes shorter on the nights of full moon, mostly due to taking roughly 5 minutes longer to fall asleep in the evening than on a night of the new moon. Levels of melatonin, hormone released by the pineal gland during the night, were lower during full moon nights as well. Some of the age and sex differences cannot be explained at this time due to imperfect experimental design – and that is OK. I’d rather see new interesting information coming out of an old data set, than never seeing it at all just because it cannot be “just perfect”.
There are many claims around about lunar periodicities in all sorts of human behavior. For some of those, there is no evidence the claims are true. For others, there is strong evidence the claims are not true. But a few subtle effects have been documented. This paper adds another set with persuasive statistics.
Is this a demonstration that there is a working circalunar clock in humans, operating endogenously, and independently from the actual moon? It’s not possible to tell yet. Those kinds of demonstrations (just like for circadian clocks) require a battery of tests, starting with documenting multiple cycles (I’d say at least three complete monthly cycles) in complete isolation, ability of artificial moonlight to phase-shift the phase of the rhythm in a predictable manner (consistent with a Phase-Response Curve), and hopefully identification of body structures or cellular components which are devoted to generation of the rhythms, with at least some hint of the mechanism how they do it.
We are far from it yet even in animals we can manipulate in lab and field studies. Much work has been done over the decades in the study of lunar and circalunar rhythms in various animals, mostly aquatic and intertidal ones. There are documented lunar cycles (but not necessarily internal lunar clocks) in a variety of organisms, including sponges, cnidaria, polychaetes, aquatic insects, and many different crustaceans including crayfish.
In the terrestrial realm, antlions possess internal lunar clocks, but many other species show modifications of behavior during different phases of the moon, including honeybees, rattlesnakes, ratsnakes, some rodents, some lizards, and lions.
The gravitational force of the moon is so weak that it can affect only very large bodies of water on the Earth’s surface. It cannot even affect smaller lakes and rivers. There is no theoretical mechanism by which any molecule or cellular structure in a human body can be so sensitive as to detect the gravity of the moon. So that hypothesis is out.
In field studies, animals can see and synchronize to the changing night-time intensity as the moon goes through its phases. But in the lab, as in the case of this study, there are no visual clues to the moon phase for the subjects, and, since they had no idea the data would be analyzed for moon phases, they probably did not pay attention to that before they entered the light-isolation lab.
With both gravity and light eliminated as potential clues, the internal clock remains the strongest hypothesis. But it’s still a hypothesis that needs to be tested before one can state with any certainty that it is the case.
As for evolutionary explanations for the existence of a putative lunar rhythm of humans? I would be very careful about this. Demonstrating that any trait is actually an adaptation (and not an exaptation or side-effect of development, or something else) is an incredibly difficult task. Just because something seems “obviously useful” does not make it an adaptation. It is an error of hyperadaptationism to pronounce a trait an adaptation just because it exists, and then to tack on a semi-plausible scenario as to how it may have been selected for. Evolutionary biology is much more rigorous than that kind of lazy armchair speculation.
Sure, if our ancestors actually had lunar clocks as adaptations, it is possible that the mechanism for it may still remain, even if in a weak state, in at least some of today’s humans. But maybe not. And like a rudimentary organ, it does not seem to have any obviously useful function for humans living in the modern society. Twenty minutes of less sleep, that’s all. But it’s good to know. So we can find good use to those extra twenty minutes, perhaps come up with new scientific hypotheses over a pint with colleagues at a local pub.
Even cows don’t like Daylight Saving Time. Come Sunday morning, when the milking machines get attached to their udders a whole hour too early, the otherwise placid bovines on dairy farms around the United States will snort in surprise and dismay. They may give less milk than usual. They could take days or weeks to get used to the new milking schedules.
We are no different. While most of us won’t be hooking ourselves up to udder pumps, our bodies next week will experience a disturbance very much like the cows’ – one that can affect our mental and physical health. The reason lies in the clash between sensitive, eons-old biology deep within our cells, and human-imposed time-keeping traditions that are barely a century old. Twice every year, when we “spring forward” and “fall back,” our bodies must do battle between “sun time” and “social time.”
Before the mid-19th century, time was more flexible. Each town and village maintained the local church clock more-or-less in sync with the natural light-dark cycles of the sun. The spread of railroads changed all that. The need to keep trains moving in and out of stations at predictable times forced the adoption of a standardized time. That, in turn, led to the formation of time zones.
Daylight Saving Time (DST)—the resetting of all clocks twice a year—was first proposed by New Zealand entomologist George Vernon Hudson in 1895, for quite selfish purposes. He was studying daily cycles in insects and wanted to be able to do more of it during daylight hours. But his idea of maximizing daylight soon spread. The first country to adopt DST was Germany in 1912. Most other countries soon followed, including the United States, which instituted DST in 1918.
The leading argument in favor of DST has always been that it saves energy. Back in the early 20th century, most energy was used for lighting. So, the argument went, placing work and school schedules within daylight hours would save electricity. People wouldn’t need to use light bulbs to navigate around their homes, offices, factories, and fields in the dark, and they would have more time in the evening to indulge in commerce and entertainment.
Today, the situation is very different. The proportion of total energy that is used for lighting is miniscule compared to other, time-independent uses like factories, computers, nuclear plants, airport radars, and other facilities that run 24/7. Energy companies themselves have measured the effect, and have concluded that DST does not save energy.
With this knowledge, some nations have started re-thinking the concept. Russia, for example, abandoned the clock change in 2011, keeping one time all year round. Iceland and Belarus did the same. On the other hand, in 2007, U.S. Congress, clinging to the notion that DST saves energy, moved the onset of DST three weeks earlier than before. That change, I think, makes a difficult transition even more stressful.
Although Congress can impose these changes, it’s a bit unclear who exactly has the right to determine whether DST is implemented. Until very recently, a large number of individual counties in the state of Indiana refused to go through the clock-changing ritual. Arizona doesn’t change its clocks at all—the only state in the union (apart from Hawaii) to defy DST altogether. This lack of clarity about who is in charge may be one of the reasons why a more sustained effort to abolish DST has been unsuccessful nationwide.
Whether or not DST saves energy is the least of the reasons why it’s a bad idea. Much more important are the health effects of sudden, hour-long shifts on our bodies and minds. Chronobiologists who study circadian rhythms know that for several days after the spring-forward clock resetting – and especially that first Monday – traffic accidents increase, workplace injuries go up and, perhaps most telling, incidences of heart attacks rise sharply. Cases of depression also go up. As the faint light of dawn starts preparing our bodies for waking up (mainly through the rise of cortisol secretion), our various organs, including the heart, also start preparing for increased function. If the alarm clock suddenly rings an hour earlier than usual, a weak heart can suffer an infarct.
Every cell in our bodies contains a biological clock which coordinates the events in those cells—for example, when gene transcription turns on and off, or when specific proteins are made. When we are exposed to a light-dark cycle that is different from what we experienced the previous days, some types of cells synchronize to the new environmental cycle faster than the others. Cells in our eyes, for example, may adjust in about a day, while cells in our brains take a couple of days. Cells in the digestive system and liver may take weeks. So, for weeks after the DST clock change, our bodies are like a clock shop in which each timepiece cuckoos at a different time of day—a cacophony of confusing signals.
Our bodies are constantly being pulled apart by conflicting demands of the natural ‘sun time‘ and culturally imposed ‘social time‘. People living in urban areas may be better shielded from the sun time than their rural counterparts, because of artificial lighting and the skyglow it produces, but nobody is completely isolated from its influence. Twelve noon according to the clock is not twelve noon according to the planet. Citizens of Barcelona and Bucarest are almost two hours apart in their perception of sun time, yet live in the same social time—the same time zone that encompasses most of Europe.
Even those of us who are lucky enough to work from home and can generally set our own work schedules are not completely immune to the effects of DST. I still have to drive my daughter to school at the time prescribed by the local clock, not by local sunlight. My colleagues have expectations about when I will pick up the phone for a teleconference or respond to their emails. I am supposed to show up for my dental appointment at 7am, not “two hours after dawn”.
But if I ever buy a cow—and that is not as crazy as it sounds since I live next door to a dairy farm—I have a plan. Of course I’ll ignore the bi-annual clock changes, which I hear many smart dairy farmers already do. But I’ll go a step further and ignore social time altogether, milking her at the sun time her nervous system can understand, probably the crack of dawn. Whatever I do, I will never make her suffer through the sudden shift of DST. And none of us human animals should suffer it, either.
Last week, in the wake of superstorm Sandy, I saw a number of people asking questions on social media (and some traditional media picking up on it) about a potential for ratpocalypse, i.e,. the possibility that hordes of rats will come out of the sewers and subway tunnels and flood the streets of New York City in a Pied Piper style. So I wrote a blog post debunking this and explaining why this will not happen, which made me a temporary expert on behavior of rats in storms, so I got interviewed in various places, etc.
As I noted at the very end of the post, my main source of information, at least initially, was a book, Rats: Observations on the History and Habitat of the City’s Most Unwanted Inhabitants by Robert Sullivan. I read it several years ago, when it first came out, and loved it. Reading it provoked me to read more on the topic, so when these questions came up, I already knew most of the answers, and knew where to look for additional information.
The book describes a year in Sullivan’s life, spent observing rats by night, and researching them by day. He went every night downtown to Fullton Street, and just stood there in the middle of two L-shaped alleys: Edens Alley and Ryder Alley. He watched rats come out at night, eat the food discarded by the two restuarants edging the alleys one on each side, fight, hide, and whatever else rats do when they are up on the surface.
The first opportunity I had to go up to New York City after reading the book was in 2007. I just could not resist! The book has no photos of the alleys, so I just HAD to go and see them myself.
My wife and I hailed a cab. Told the driver: Edens Alley. Driver: Hmmm, this is my first day on the job, do you know how to get there?
This was before I had iPhone, GPS, Google Maps…. I pulled out an old-style map, printed on paper, and gave the driver turn-by-turn directions. Once we got there (after making several circles around the area), the driver refused to take any money. I forced him to take double the amount of the fare. He did well for the first day as a NYC taxi driver. This place was hard to find. And off the mid/up-town grid.
Of course, this was in the middle of the day. I did not expect to see any rats there at that time. If I did, that would be an indication that the underground population is astoundingly large, forcing some of the sub-dominant individuals to forage during the day. But I was looking for traces of rats, and for holes and crevices from which they emerge at night, for bags of garbage full of Chinese food, and I took the pictures. I had the pictures stashed away in my Dropbox for more than five years. This is the first time they see the light of day. See for yourselves:
The short answer is: some rats drowned, some survived.
The complicated question, how many drowned and how many survived, is probably impossible to answer. But we can speculate using the information and knowledge we have in our possession. But things we really need to know, we don’t – information is just not available (and some of it never will be).
How many rats are in NYC?
Nobody knows. Nobody seems to even be attempting to estimate.
Beware of the myth that there is one rat per person. That is a very old myth. It started in 1909 when W.R.Boelter published a study of rats in England. He asked farmers (but never bothered to look in the cities) to estimate how many rats they have in their fields. From that informal survey, Boelter came up with an average of one rat per acre (yes, of agricultural land). At that time, there were 40 million cultivated acres in England. From that, he estimated the total population of rats on agricultural land to be about 40 million. Completely coincidentally, England in 1909 also had a population of 40 million people. So, the 1:1 ratio stuck. And it has been repeated for more than a century, by media, by scientists, by United Nations, by pest control companies, by health departments, and apparently everyone else.
In 1949, Dave Davis did a systematic study of rats, by trapping and capturing them, and estimated that rat population in New York City was only about 250,000. Not even close to 8 million.
An aside – I have an indirect personal connection to Davis. For a while he was a professor in the Department of Zoology at NCSU, that is, in my own department. At the time he was ready to retire, in the 1970s, he was actively working on daily and seasonal rhythms in various animals. He used to work with Curt Richter before, at Johns Hopkins, and Curt is one of the pioneers of chronobiology. David sent some woodchucks on a ship from Philadelphia to Australia. While on the ship, rats kept EST time, but quickly re-entrained to the Australian local time once they arrived there and were exposed to ambient light. Although the field was still very young, Davis’ work made the rest of the department aware of it (they did not think it was Biorrhythms silliness, as many assumed at the time), so they were interested in hiring a replacement who was doing something similar. So they hired this bright, young lad from Texas in his spot – two Science papers already published and he took only 3.5 years to get both MS and PhD. The new faculty’s name was Herbert Underwood. Two decades later I joined the Underwood lab. The rest is history.
Anyway, back to rat population. Estimates vary wildly, to as high as 32 million. Nobody really knows.
New York City is old. It was built and rebuilt. New buildings were built on top of the old ones. There are old, buried tunnels, rooms, chambers, now not accessible to humans but perfectly accessible to rats. Gradually, the city dug out more and more sewers, more and more various pipes, more subways and other tunnels. Thus more places for rats to nest. We gradually built comfortable homes for more and more rats.
The rat population is not evenly distributed either. They tend to be where poor people live, and where the restaurants are. That’s where there is food.
And not all rats go to the surface. Rats are pretty loyal to the place of birth, and rarely venture more than about 60 feet from it, throughout their lives. If displaced, they can find their way home from as far as 4 miles, but for a foot-long animal, that is an extremely long distance.
If they can get food down under, e.g., from subway passengers throwing out uneaten food onto the tracks (which they do), rats never need to go up to the surface. They never get captured and counted in surface surveys.
Can rats swim?
Yes, rats are strong swimmers. They can even dive for a little while – see this video: if a domesticated rat can be trained to dive (and enjoy it), I assume that a wild rat can do it when its life is threatened:
The thing is, swimming in a water maze in the lab, or on the surface of a body of water is one thing. Swimming upward, against the powerful stream of water streaming downward is a completely different thing. They may be strong swimmers, but they are not Johnny Weissmullers.
MTA workers pumping out water from subway tracks at South Ferry subway station in New York, Tuesday, October 30, 2012. Photo: Hiroko Masuike, NYTimes
There are many ways up to the surface, but they all go up. And if the water was mainly gushing into the tunnels from above, from the streets as Sandy was flooding, they would have had to swim or dive up narrow pipes, essentially vertically up against the water. No way. Those guys drowned.
To go up to the surface, rats need to know the way to the surface. Rats know their own territory very well. But rats that never go to the surface do not know how to get there. They may still want to instinctually go up, but they don’t know the way so would have to get lucky to actually find the stairs and then fight their way up against the gushing water.
Rats already on the surface would probably be fine. The water and wind from Battery would carry them north until they reach the dry ground. They can certainly stay on the surface. Salty water is denser than fresh water, so they would find it even easier to stay on the surface, though their eyes may not like all of the salt.
What was flooded, when and how?
Right now, we do not know exactly where, when and how the water entered the subway tunnels, sewers, etc. MTA site does not provide much information. New York Times does not either – they are concerned with information useful to people, e.g., when will the subway open again, not where, when and how the subway initially flooded. Most likely the water came from above, from the flooded streets after sea water rose high at the Battery and the East side. This is important. It is easier for rats to float on the surface of water rising from below, than to fight against the water falling from above.
Also, most of Manhattan (and rest of NYC) did not flood at all. Most of the rats probably survived just fine where they were.
Who lived, who died?
So, from above, we can speculate that many rats survived. Some were never affected by flooding. Some were on the surface already and managed to run or swim to the higher ground. Some knew their way out to the surface and made it there. Rats are smart and crafty – if they can find a way to hide or go out, they will.
But some rats certainly drowned. Those are the rats that live deep inside holes we never know about, let alone visit. Rats that never go up to the surface. Rats that had the misfortune to have to try to escape essentially vertically up against strong gushing water.
There is a rule of thumb – if you see a rat on the surface during the daylight time, this means that the underground population is enormous. And I see them every month I go up to New York. When the rats are crowded, dominant rats take the best spots. If the population forages on the surface, dominant rats forage during the night. Subdominant (or submissive) rats are temporally displaced to the daytime shift.
This is important. If Sandy started to flood the tunnels during the day (and nobody knows, or makes public, this information as the subway was already closed to people by then), it will be the non-dominant rats who are on the surface, and thus more likely to survive. If the flooding started at night, it will be dominant rats on the surface, floating away into safety. Dominant rats are more likely to be able to relocate and survive in other places where they have to compete with locals. Non-dominant rats would have a much harder time finding a new home.
So, my guess is that most of the rats survived. But quite a large number of rats drowned – depending on exact location, depth, how much they know how to get to the surface at all, their exact route to the surface, and their status in the social hierarchy.
Me and an enormous spider, at the Natural History Museum in Berlin, 2008.
A couple of decades ago, my wife and I worked on a horse farm where everyone was explicitly instructed not to ever clean the cobwebs inside the barn. Sure, the owners themselves would occasionally, very carefully, almost surgically, remove a few targeted old cobwebs here and there, but the majority of the webs remained up at all times. Explanation? Spiders don’t bother anyone, while flies and mosquitoes bother both horses and humans.
On the other hand, for balance, there is an old Serbian proverb that goes like this: “If there were no wind, spiderwebs would cover the sky”
I assume this is said every time someone complains about the strong eastern wind, Koshava, that sweeps through the country in autumn.
And this situation – spiderwebs covering the sky – is something that happens in Mark Twain’s story Some Learned Fables, For Good Old Boys And Girls, featuring Herr Spider as one of its key characters. I read Twain’s short stories over and over again as a kid. Still love them.
Why are we so enchanted by spiders, in real life, in mythology, and in popular culture? I certainly am, always was.
There were Little Miss Moffet, and Itsy Bitsy Spider.
Of course I knew about Arachne and the beautiful myth of the origins of the callipygous Shenora Spider (does such a species even exist in reality?).
And then there are spiders in literature. I was scared by the Spider-Man in John Wyndham’s The Chrysalids. I fought the giant spiders of Mirkwood when I played The Hobbit computer game on Sinclair ZX Spectrum back in 1981 or so, after I have already read the book both in Serbian language and the original English. There was Shelob in Lord of the Rings, and Aragog in Harry Potter.
And of course, the best spider in all of history – Charlotte!
Charlotte. She could write.
Today is the 60th anniversary of the first publication of Charlotte’s Web, the beautiful, haunting story of a talking pig and a writing spider.
Interestingly, growing up in Yugoslavia the first 25 years of my life, I have not heard of Charlotte’s Web until I came to the States. But then I had kids. And kids loved to watch the movie over and over again. So I read the book.
And to this day, occasionally, spontaneously, I start singing “Isn’t it great that I articulate!” An important and heart-felt sentiment for a writer for whom words are toys.
A couple of months ago, I went to the American Museum of Natural History in New York City (thanks for the tickets, you know who!) to see their new exhibit – Spiders Live. Yes, “Live” is a good description – there are plenty of living specimens in there, many quite fascinating.
As usually happens in museum exhibits, there was plenty to learn about what we know. Anatomy, physiology, ecology, evolution, geography, behavior. Sure, there were a couple of non-spiders there, like scorpions, but it was clearly explained exactly why they are not spiders and how they are related.
One could see a short video showing how Gladiator spider catches its prey by throwing a carefully counstructed web trap on it, like this:
And they mentioned the Bolas spider which catches its prey by lassoing it in with its bolas-like ball of silk:
Interesting – to me at least, as a chronobiologist – is that the Bolas spider uses its circadian clock for an interesting function – it produces different blends of chemicals in its pheromone at different times of night (pdf) to coincide with different times when two different species of moths are flying around, each species attracted to a specific mix of aromatic chemicals.
But beyond learning facts, I was also looking at the ways the exhibit tries to include the scientific process – how we know what we know about spiders? I was looking for, perhaps, descriptions of ingenious experiments on the courtship signaling in wolf spiders, or the research on unique social, colonial spiders. Nope.
There was a part, at the end, which described how scientists collect spiders in the field, how they catch them, preserve them and label them.
And then I saw what I was really looking for. Yes! They did it! The exhibit had a really nice description of my favorite spider research ever! And there it was, The Charlotte’s Web connection, and my own personal connection! I talked about it at the last #TriSciTweetup at the NC Museum of Natural Science in Raleigh NC, for the inaugural Lightning Talks with Brian Malow on Thursdays at the Daily Planet Cafe:
Back in 1948., zoologist H. M. Peters was studying how spiders spin webs. He was getting tired as he had to do all of his research late at night, when spiders spin their webs. So, he asked his friend Peter Witt, a pharmacologist, if there is anything that he could give to spiders that would make them spin during the day. Peter suggested amphetamines. It did not work. Spiders kept weaving at night. But, oh my, their webs looked crazy! They were like impressionist art!
Peter Witt was an amazing person, a wonderful man. I had the fortune to meet him once, in 1998, just a couple of weeks before he died. He was the Head of the institute for brain and behavior at Dorothea Dix hospital in Raleigh, now unfortunately closed.
Intrigued by the results his friend Peters got when giving spiders amphetamines, he turned his own research into that direction, using spider webs as windows into the way different chemicals affected the nervous system. Some of those were pharmaceuticals of the day. Others were drugs found relatively easily on street corners back in the 1950s and 1960s. Both were of interest to science, of course, for different reasons.
Different drugs had different effects on the shapes of the web. In high doses, almost every drug resulted in highly irregular webs. But at carefully chosen lower doses, there were some interesting differences. For example, under the influence of caffeine, the webs were vertically shorter but horizontally wider, as spiders made larger angles between the radial spokes of the web.
The most striking was the effect of LSD-25. Yes, LSD. This is the only drug which resulted in webs being more carefully weaved and more perfect than the controls.
Charlotte? Is that you?
Many years later, I was teaching a lab at NCSU in animal physiology. Part of the lab was a project, done by students under my supervision. Some students did projects on humans – each other. But the other half used animals. Invertebrates, as there was no time to get an IACUC (institutional animal care and use committee) approval for use of vertebrates (that is a long and difficult process).
A spider web on pervitine
One of my students decided to use Peter Witt’s experimental protocol, applying a chemical that he never used way back then – serotonin. Result? Spiders made decent webs, but they took about twice as much time to make them. They went slow about it. They made perhaps half of the twists of the spiral before deciding that was the end, leaving about twice as much space between the loops of the spiral.
Spider brains are large and complicated. They are so large they can’t even fill just the head, a part of them fills the thorax. Of course, spider brains are difficult to study. Not to mention that we do not have a spider genome sequenced yet so we do not have the tools to monitor what is happening in a spider brain. Thus, this line of research has been largely abandoned.
But it was not all in vain. Apart from being able to categorize substances along the lines of their effects on spider webs (often corresponding to their effects on human brains), this method now has a place in agriculture. Placing a few spiders in a field or orchard overnight and taking a look at the webs in the morning can tell the researcher if there are pesticides there, and perhaps which class of pesticide if not the exact kind.
Perhaps there is something in the air that can induce a spider to write “Terrific” and I’d love to know how it does that.
One of the most effective methods for the control of spread of malaria is the use of bed nets infused with insecticides. Most species of mosquitoes (the Anopheles genus) that carry the malarial parasite (Plasmodium falciparum) are considered to be strictly nocturnal – they are active only during the night.
Thus, sleeping under the net provides protection against getting bitten by the insect vectors of the disease. The net does it in two ways – by providing a mechanical barrier between the mosquito and the human, and by killing mosquitoes that get in contact with the infused insecticide.
As we have learned many times, often the hard way, evolution tends to find a way around such tricks. A number of Anopheles species or local populations have evolved resistance to pyrethroid insecticides usually used in the nets. Yet, the mechanical protection of the net should still be effective, right?
Not so fast! A new study published in September 21 in the Journal of Infectious Diseases documents a behavioral change in a local mosquito population that effectively works around the safety protection of bed nets. What do they do that’s new? They changed the time of day when they bite!
Malaria-carrying mosquitoes are thought to all be strictly nocturnal. Recently, this dogma has started to be questioned, mainly because the rates of malaria did not significantly diminish in areas where bed nets have been implemented. Perhaps they fly and bite during the day, yet nobody bothered to test that hypothesis yet? A previous study noticed a shift in timing of activity and biting from middle of the night into early night. This study was quite systematic – repeating the experiment in two locations in Benin at three time-points: before, during and after the full implementation of bed nets in both locations.
Chronogram of the experiment. Translation for humans: 'chronogram' is an "aren't we sophisticated in our clever use of silly, opaque, uneccessary jargon" version of 'timeline'.
What did they do? They collected mosquitoes in large numbers and recorded the time of day they caught mosquitos. In addition, they used morphology to identify the genus, and PCR to identify the species. Every single mosquito was Anopheles funestus. They tested the caught mosquitoes for pyrethrin resistance and did not detect any – every single mosquito died. Thus all the changes were strictly behavioral.
How did they collect them? They placed humans in strategic places as living targets. It looks pretty much like this video, except they actually captured the insects into vials, then transferred them into small bags:
During the period of just a few years as the bed nets got implemented in the two villages, local mosquitoes dramatically shifted the timing of activity. Instead of 2 or 3am, they now predominantly bit humans around 5am:
Shift in timing in mosquito activity in two locations over three sampling periods.
What does that mean?
First, we don’t know yet if this was an evolutionary (i.e., genetic) change or a purely behavioral change. It is possible that there was quite a lot of genetic variation in timing of activity in the population a few years ago and that the bed nets provided a selective regimen that skewed the population to consist mainly of late night and dawn-active individuals. It is also possible that there is sufficient behavioral plasticity in the mosquito allowing it to learn the new best time of day to go out foraging. I’d love to see the mosquitoes placed in isolation chambers to monitor purely genetic patterns of circadian rhythms of activity.
But let’s think more in ecological terms. There are several players here: the Plasmodium parasite, the Anopheles vector, the human host, and predators that eat mosquitoes, notably bats. I have written at length about this a few years ago. Here’s a simple schematic of how the system works when undisturbed:
A crude schematic of possible timing of activity in this ecological system
If the mosquito shifts to almost dawn, what happens?
First, the humans are up and about, outside of nets, readily available to bite. If the humans are healthy but mosquitos are carriers, this is a good way to transmit malaria to them.
But the humans who are sick, the sources of malaria, are still not available. At the times when they undergo “quaternary fevers”, which are the times when malarial parasites are present in their blood (I explained this in great detail before), they are safely hidden by the nets in the middle of the night and they are not bitten by late-biting mosquitos.
Second, a mosquito that bites a human around dawn is much more likely to get detected by that human and be swiftly turned into a small, bloody mush.
Third, while a mosquito that flies around dawn may be able to avoid some of the bats (though not all of them – many bats hunt until the break of dawn), they are now increasingly vulnerable to other predators – frogs, lizards and birds – that tend to hunt at dawn.
As it often happens, there are pros and cons when it comes to evolving new adaptations. The bed nets are now selecting for new adaptations in mosquitoes. It is hard to predict what will be the pros and cons of those adaptations for human health, or the pros and cons of those adaptations for mosquitoes and their survival, or pros and cons of these adaptations to insects’ predators. Future research on this will be both very interesting to watch and very useful for control of malaria.
The week was too busy to finish this on Friday. Then on Saturday the news broke that Neil Armstrong died – something I wanted to highlight as a special topic – so I decided to wait another day and give people a chance to wrote posts and articles about Neil. So, with a delay, the weekly linkfest is here!
Blog of the Week:
We are all in the gutter is a an astronomy and astrophysics group blog. The title of the blog comes from the quote “We are all in the gutter, but some of us are looking at the stars.” from Lady Windermere’s Fan by Oscar Wilde. Emma, Niall, Rita and Stuart are astronomers, astrophysicists, star-gazers and space geeks at various career stages, having fun with their blog, exploring the universe from every angle they can possibly think of.
I hate the phrase “living fossil.” The term should be eradicated from the vocabulary of science writers, and anyone who employs it should be promptly encased in Carbonite. “Missing link” is the only slogan that pisses me off more. My acute allergic reaction to the idiom may be a little overwrought, I admit. But, to me, “living fossil” is nonsense that obscures more than it elucidates. Take the coelacanth, for example….
Anyone who has ever attended a holiday parade or gone on a summer vacation knows that cultures tend to create their own seasonal patterns. In much of Western culture, December is a time of much celebrating and feasting, while similarly wintry January is relatively dreary and dull (after New Year’s celebrations subside). This raises a question: how do the behaviors and culture of a society affect the animals that depend upon that society’s garbage for their food? The progressive encroachment of human settlements into the habitats of wild animals has opened opportunities for animals to avail themselves of human refuse. A raccoon in North America is likely to find a juicy watermelon rind in July and leftover turkey remains in November. Perhaps equally enticing for a roving dumpster-diver, but by no means nutritionally equivalent….
The idea of a red sky at night used to invoke beautiful images of vibrant sunsets, the product of warm sunlight bathing the sky near the horizon. The adage of “red sky at night, sailor’s delight” refers to a calm night ahead; a red sunset suggests a high-pressure system in the west is bringing calm weather. But red skies at night have taken on a new meaning in recent decades. As outdoor lighting become increasingly prominent, our night skies are gradually turning from black to red….
One of the reasons I love astronomy is that it doesn’t flinch from the big questions. And one of the biggest is: are we alone? Another reason I love astronomy: it has a good shot at answering this question…
…..The other explanation is that the Cretaceous ended when, 65 million years ago, an asteroid (or asteroids) slammed into the earth, right across the future-Gulf of Mexico at the tip of the Yucatan Peninsula. Not only did the impact and resulting fallout from that asteroid kill the dinosaurs, it also wiped out huge quantities of marine life, including many of the “tiny marine plankton with carbonate skeletons” (I’m guessing some version of Coccolithophore? Anyone?) that would become the rich soil that slaves would farm on land their ancestors would inhabit in voting districts that would favor Democratic candidates around the turn of the second millennium of the Common Era……
There’s a lot not to love about The Dark Knight Rises, the crazyish new chapter in the latest Batman cycle: a series of actions and explosions so unconnected that they make a Rorschach test look like a syllogism by comparison; Marion Cotillard’s death scene, which lacked only her eyes rolling up and her tongue lolling sideways from her mouth to equal those put on by toddlers on playgrounds; and Christian Bale’s Batman growl — close your eyes and you think Cookie Monster is saving Gotham City….One thing the movie got right, though, is its focus on the infrastructure systems that serve as the beating and vulnerable heart of our urban existence. Every major plot point directly relates to the built environment and the networks that make every element of our lives possible….
I have always known that I loved science, that delicious alliance of imagination and methodical testing that could help you figure out something about how a piece of the world worked. However, being born at the tail-end of the 1960s, I grew up in a culture that wanted me to know that girls were not supposed to like science. In fact, between toy commercials and TV shows, teachers and peers, I got the message pretty quickly that science is not something for girls. Rather, girls should turn their attention to more important matters . . . like being properly feminine. There was a way that girls were supposed to be—neat and tidy and pretty and pink and quiet and well-behaved. I was not any of those things. I didn’t want to be any of those things. I didn’t know how to be any of those things. And, as far as I could tell, trying to be those things was not going to help me get my hands on the science-y stuff that I wanted. So what was the point?….
…….During a panel at the Aspen Environment Forum in Colorado, as she describes here, Emma piqued Wilson with her talk of making more nature — of expanding our definition of the natural world to include places humans have invaded, altered, and restored. Spending billions trying to return coastal areas like the Everglades to pre-Columbian “purity,” she added, is a lost cause. Better to invest in upslope reserves, and perhaps even learn to admire the tenacity of invasive species…..
With every passing year, men are increasingly likely to transmit new mutations to their children, according to the largest study yet of the so-called paternal age effect, published yesterday in Nature. The findings could help explain why older men are more likely to have a child with autism or schizophrenia than are younger men, the researchers say….
I am a nerd. I was a nerd. I will be a nerd. Perhaps in kindergarten I wasn’t, where nerdom had difficulty establishing itself among the simple lessons of the alphabet, counting, and colors. In kindergarten, we are more or less the same in deficiencies and achievements. But after that, I am pretty confident my geek flag flew. I cannot remember ever being a bad student. Repeated straight A’s and the honor role defined me….
Do you believe in dog? is a brand new blog. It is written by two dog researchers, one in New York City, the other in Yarra Valley just outside of Melbourne, Australia. Julie Hecht you may already know from her wonderful blog Dog Spies, her writing in The Bark, or her research which we covered here at SciAm. She studies (and teaches about) dog cognition. Mia Cobb, the Australian, did her research in animal behavior on birds and ants, but now works on issues of dog shelters, welfare and performance science of working dogs. What is the coolest thing about the blog is that the two of them write for each other, addressing each other in each post, thus teaching and learning from each other in a dialogue to which we are all invited to participate in and contribute.
WARNING: This post contains my blood and guts, literally. If you’re squeamish, I recommend skipping this one. What follows is my journey through the operating room at Columbia-Presbyterian on July 18, 2012. Apologies, but I couldn’t help starting off with yet another pop culture reference (this time from Wes Anderson’s Rushmore)….
I, and others, have pointed out that there are three aspects of evolution: evolution as fact, evolution as theory, and evolution as path. Evolution as fact refers to the historical reality that species are related through common ancestry. This is supported by a massive amount of evidence from a wide array of independent sources. Evolution as theory refers to the proposed explanations for how “descent with modification” occurs — mutation, natural selection, genetic drift, etc. Evolution as path refers to the actual patterns that have occurred during the history of life, such as when certain events (e.g., branching points, extinctions, etc.) took place, how lineages are related, when and how many times certain traits evolved, and such. The important point is that these three components are largely independent…
There is a structurally integral part of my psyche that is the keystone to my existence. I am not sure how it was placed in such a vital position, but it seems this part of me is embedded in my DNA. Something that I can never remember being without. The absolute and total fascination with the natural world….
The assassination of Abraham Lincoln on April 15, 1865 shocked a nation still recovering from four years of bloody civil war. Along with the hunt for his killers and the uncovering of the assassination plot against the President and several other members of his administration, there was also the logistic nightmare of his funeral and the need to transport the President’s body by train from Washington D.C. to his final resting place in Springfield, Illinois. Since the funeral train would retrace the route that Lincoln had traveled to Washington following his election, the body would be viewed by millions of mourners along the way during the numerous planned stops. All of which raised the question of how to keep the body preserved long enough to reach its destination. Considering the fact that funeral embalming was a relatively new development at that time, some very special arrangements needed to be made…
I have a confession to make: I cringe a little every time I see a school science or science outreach program justified by saying something like, “Young children are natural scientists, truly curious about the world” (That particular quote is from the Delaware Museum of Natural History). I feel like a curmudgeon about it because it often comes with really good intentions to get students actively involved in doing science (something I definitely support)….
The last time I ate a hamburger, I spent the night in the emergency room. There wasn’t anything wrong with the hamburger itself—aside from being a bit overdone—but it sent me into anaphylactic shock. It wasn’t always this way…
Have conservation scientists become carried away, touting the ecological benefits of wolves where there are perhaps — dare I say it? — not as many as we believe there to be? Perhaps some people in the media, and even some in science, have gotten carried away with the ecological changes that wolves are actually capable of mediating, says globally-renowned wolf biologist L. David Mech in his most recent paper “Is science in danger of sanctifying the wolf?” …
If you ever find yourself in a pub with me, chances are that at some point, the conversation will turn to death. Not just death, but the terrifying and horrible ways people have succumbed to it in the past. I have often heard a story retold about a man who attended the execution of his friend during the French Revolution. Seconds after the guillotine fell, the man retrieved the severed head and asked it a series of questions in order to determine whether or not it was possible to retain consciousness after decapitation. Through a system of blinking, the victim allegedly communicated his message back to his friend. The ending to this story changes according to the whims of the narrator… or perhaps the number of drinks he or she has consumed by that time. I wondered: was this the 18th-century equivalent to an urban legend? Or could there, in fact, be a degree of truth in this ghastly tale?….
Dragons aren’t real. At least, the fire-breathing wyverns and coiling wyrms of medieval lore aren’t. Those reptilian menaces were products of superstition and pre-scientific ideas about prehistoric creatures. They were ugly amalgamations inspired by our fears and actual fossil remains of long-extinct mammals and dinosaurs. But in the early 20th century, reporters excitedly relayed the discovery of what quickly became known as the Komodo dragon – ten foot long lizards that had coexisted with humans on South Pacific islands for thousands of years, but had only just been recognized by western science….
Rrrr… RRR… Thack! Thack! Thrusting his front legs skyward, the male jumping spider shakes his rear end to send thumps, scrapes, and buzzes through the ground. He’s playing for a female’s attention, dazzling her eight eyes with semaphore while drumming out seductive seismic signals. A few missteps could turn the spider’s performance into a dinner show—with the star as the main dish. The ferocious female demands precise choreography, set to a groovy beat that UC Berkeley behavioral ecologist Damian Elias is working to decipher….
Kristina Killgrove (Twitter) is a bioarchaeologist. Her blog Powered By Osteons covers a wide spectrum of topics on archaeology, bioanthropology, and the classical world. But what it has the most, and is most exciting, are bones. Lots of bones. Human bones. Skulls and femurs and pelvises and what we can learn about the past from studying them.
…All the Mars rovers so far, from the trailblazing Sojourner to the overachieving twins Spirit and Opportunity, have been extraordinary exploratory robots, but Curiosity represents an ambitious new extreme. Most obviously, it’s much bigger: Curiosity weighs almost a ton and is the size of a small car, whereas Spirit and Opportunity were half as long and a fifth as massive and Sojourner was not much bigger than a large cat….
…..In fact, as someone who has a PhD in science but has been a writer longer than I’ve been a scientist, I’d argue that it might be better not to have specific training in science if you’re reaching for an audience of nonscientists, depending on what your goal as a writer is. If your goal is to tell a great science story that keeps the nonscientist reading and thinking, “wow” or “I get it,” then scientific training might be an anti-requisite. If your target is critique and analysis of science, then scientific training could be quite useful as long as you don’t let your deep background blind you to what your readers might not understand as well as you…..
….The little prince isn’t alone in carrying insights that are lost on a child. What of Alice in her wonderland and mirrored adventures? Alice’s story may have been born from a tale told to children one lazy afternoon, but it became much more: a deep philosophical meditation….
Even now, there are those who claim that the long-jump record of 8.9 meters that Bob Beamon set in 1968 was so crazy awesome because he accomplished it in Mexico City, which is almost 8,000 feet above sea level. The argument is that the air is thinner, and so there is less air resistance, and Mexico City is further from the center of the earth, and so the gravitational forces are smaller. Does any of this have any impact? And if so, does it really matter?…
It is a widespread misconception that, as we developed the technology to reshape our environment to our preferences, human beings neutralized the power of natural selection. Quite the opposite is true: some of the best-known examples of recent evolutionary change in humans are attributable to technology. People who colonized high-altitude environments were selected for tolerance of low-oxygen conditions in the high Himalayas and Andes; populations that have historically raised cattle for milk evolved the ability to digest milk sugars as adults….
I’ve been working with photographer Chris Arnade to document stories in Hunts Point, Bronx and often-ignored areas of New York City. Over the course of the last year, we have noticed the impact the city’s Stop and Frisk policy has on the neighborhood. Recently, we made the decision to start documenting that in action should we see it. This Sunday, we did:…
I’ve mentioned here before that I went to fundamentalist Christian schools from grade 8 through grade 11. I learned high school biology from a Bob Jones University textbook, watched videos of Ken Ham talking about cryptozoology as extra credit assignments, and my mental database of American history probably includes way more information about great revival movements than yours does. In my experience, when the schools I went to followed actual facts, they did a good job in education. Small class sizes, lots of hands-on, lots of writing, and lots of time spent teaching to learn rather than teaching to a standardized test. But when they decided that the facts were ungodly, things went to crazytown pretty damn quick….
I’d like to get something off my chest. It’s been bugging me for a very, very long time. Sherlock Holmes is not a sociopath. He is not even a “high-functioning sociopath,” as the otherwise truly excellent BBC Sherlock has styled him (I take the words straight from Benedict Cumberbatch’s mouth). There. I’ve said it…
In writing my previous post on The Murderer Invisible, I started thinking again about the relationship between something being “transparent” and something being truly “invisible”. Most of us can appreciate that, under the right circumstances, a transparent object like a glass window can be very hard to see, but most of us also appreciate that glass is not even close to fitting the popular perception of invisibility. In fact, though we encounter plenty of transparent things in nature, we don’t encounter invisible things….
Beatrice the Biologist says this about itself: it is “part science blog, part comic, and part incoherent rambling: science edutainment at its finest.” Written – or rather drawn – by Katie McKissick, each post is a visual delight and will make you chuckle…and learn.
In a hotel ballroom on the campus of the University of Pennsylvania on a midsummer Saturday in 2010, an unusual roll call was under way at the Family Conference for the Foundation for Retinal Research. Betsy Brint, co-head of organization, was calling out what sounded like code words – CEP290, GUCY20, LRAT – and for each one, a few people would stand up, excited, then form little groups. After all 18 abbreviations had been called, representing the genes known to cause Leber congenital amaurosis (LCA), a few sets of parents were left standing. Troy and Jennifer Stevens, of Chino, California, were among those whose childrens’ genes and mutations were still a mystery….
…..The next sections jump into “evolutionary-biological interpretation,” which we took to mean science, and which gave us the distinct impression that the author’s research of sex stopped at the work of William H. Masters and Virginia E. Johnson instead of starting there. That’s not surprising, though. ….
Snakes. In the ancient Maya ruins where I’m working at with archaeologists, the creatures we fear most are probably the snakes. That fact might sound like the punchline to an Indiana Jones joke, until you hear about the most dreaded serpent here in the jungles of Belize. The fer-de-lance is likely the deadliest snake in Latin America, packing an amputate-if-you’re-lucky bite if it goes untreated. Its long fangs can go right through a boot, and it’s aggressive – unlike many snakes that seem more afraid of us than we are of them, the fer-de-lance won’t hesitate to strike. ….
….There’s no way around it. Even with the huge amounts of heat Aquaman would produce as he burned through his daily 48,000 Calories, he is going to get cold. With little body fat and no fur to speak of, his heat retention potential is pitiful. Fortunately, there are plenty of simple solutions to the thermal problem. Unfortunately, almost all of them involve visible changes to his physique….
….We quickly found out that something that seemed simple – catching a bunch of pretty colored insects and putting them in boxes – was actually demanding and nearly endlessly complex and mysterious. A lot of the butterflies that were the coolest, the rarest, the most beautiful, lived in strange places – treetops, the edges of swamps and streams, sunlit clearings in deep woods – and only flew in certain seasons and specific times of the day – early spring, late afternoon. We learned why – mating rituals, foodplant availability, lifecycle requirements. We didn’t just read, we observed. We learned that the books were not always right – insects are really variable and behave differently in different locales. We developed hypotheses, collected information that supported or contradicted them. We learned, at least concerning a couple dozen species of butterflies in the part of upstate New York where we lived, how nature worked. Nature taught us the science we needed to use, and science taught us what there was to know. (Not that we knew enough to call it “science, “ of course.) It was like the world had opened up. ….
She had only been in the hospital twice in her life: once when she was nine and now, 60 years later. She had gotten tonsils out then. She was getting tumors out now. Her abdomen hurt when she was awake. Her abdomen would also hurt during exploratory surgery, although she wouldn’t be able to feel it under general anesthesia. Her body would feel it, though, and could respond by dangerously spiking or plunging her vitals. She needed an epidural before surgery to keep the pain under control…..
The start of the story is this: In December 2008, a 23-year-old research assistant named Sheri Sangji accidentally set herself on fire while working in a chemistry laboratory at the University of California, Los Angeles. She died 18 days later in a hospital burn unit….
Delicately and cautiously, health authorities in the United States and other countries are beginning to open up a difficult topic: Whether the extraordinary ongoing epidemic of whooping cough, the worst in more than 50 years, may be due in part to unexpected poor performance by the vaccine meant to prevent the disease….
Power was restored today in India, where more than 600 million people had been living without electricity for two days. That’s good news, but it’s left many Americans wondering whether our own electric grid is vulnerable. Here’s the good news: The North American electric grid is not likely to crash in the kind of catastrophic way we’ve just seen in India. I’m currently interviewing scientists about the weaknesses in our system and what’s being done to fix them and will have more on that for you tomorrow or Friday….
…Dogs with compulsion may pace, chase imaginary flies, or lick their flanks until they get sores, despite their owners’ best efforts to make them stop. Certain breeds are especially vulnerable. A staple of canine compulsion is tail chasing, which frequently strikes bull terriers and German shepherds. On one forum, user MatrixsDad complains that his German shepherd “is constantly chasing and barking at her tail…She comes up and puts her backside against anyone who’s standing around so she can get a better view of her tail before she starts chasing it.”…
Science Decoded is a wonderful mix of science, book reviews, and thoughts about the media, written by Erin Podolak, alumna of the University of Wisconsin program for Science Journalism, and now a science writer for The Dana-Farber Cancer Institute.
In the summer of 1920, a 29-year-old son of Minnesota farmers docked his boat (acquired with stolen money) at a small island in New York City’s East River. One by one he hired out-of-work sailors to crew for him. And one by one, he shot them in the head with a Colt .45 and dumped their bodies in the water. Before he was executed in 1930, Carl Panzram put the sailor body tally at 10 although he estimated that was only about half his total murder count. “For all these things, I am not in the least sorry,” he wrote in a jail house confessional. “I was so full of hate that there was no room in me for such feelings as love, pity, kindness or honor or decency.”…
Many people think they know the story of the very first ‘marathon.’ Pheidippides, reputedly the fastest man in the Greek army, allegedly ran from the battlefield at Marathon twenty-five miles to Athens in 490 BCE to announce a Greek victory over the invading Persians. Bolting into the Athenian assembly, he shouted, νικωμεν (nikomen), ‘We have won!’ and promptly keeled over dead….
…Two-thirds of the jobs on the islands are in the service sector. The tourists come, of course, because of the amazing plants and animals. They contribute money directly to conservation efforts, and their patronage boots the economy and allows the government to set up its own conservation management systems. That’s all great, except — more people also means more: ships, construction, roads, vehicles, hotels, restaurants, water and energy use, garbage, and sewage. All of that threatens the habitats and health of the plants and animals. In other words, the whole thing is unsustainable. The growing economy in the Galápagos is simultaneously supporting more science and conservation efforts and destroying the things that need to be studied and conserved. The economy is eating itself….
Sometimes what looks like friendly behavior is really an attempt to get one’s neighbor eaten by a wolf before oneself. Sheep, for instance, seem cozy enough in their flocks. What’s a better way to travel than surrounded by 100 percent merino? But the real reason they stick close to their neighbors is to save their own woolly rear ends…
Some folks just can’t help being loud in bed, but noisy liaisons can lead to a swift death… at least for a housefly. In a German cowshed, Natterer’s bats eavesdrop on mating flies, homing in on their distinctive sexual buzzes….
Tucked behind a hill in rural Trempealeau County, farmland undergoes an industrial transformation. Outside this city of 1,300, Preferred Sands turns Wisconsin’s sandy soil into a hot commodity. A wall of green trees opens to a vast expanse of sand buzzing with activity. Excavators mine and conveyors carry the sand from towering stockpiles up into the processing plant. Every week, this facility ships 7,500 tons of sand by rail to oil and gas fields in Texas, North Dakota and Pennsylvania. …
Steven Pinker has posted an important essay on group selection. You can gather its thesis from the title, “The False Allure of Group Selection.” Since I am on record saying that group selection (really, multilevel selection) was critical to the evolution of language, I read the essay with strong interest. Let me say right off that I was astonished to find that the essay makes no remarks about the evolution of language. Pinker is a famous proponent of language’s evolutionary origins and biological basis, but he says nothing of group selection and language. Instead he criticizes ideas that group selection explains religion, culture, and nations. I am skeptical of those claims too. Pinker is a fine writer and I got several chuckles out of his examination of various shallow appeals to group selection. Was I laughing at my own doom?…
Thirty-one years into the HIV epidemic, health authorities are finally starting to sound hopeful about the prospects for curbing it. If that sentence sounds bitter or sarcastic, it isn’t meant to be. Rather, it’s an honest assessment of how long and frequently depressing the era of HIV and AIDS has been, and of how much misery it has spawned. But it also acknowledges reasons to think that maybe, just maybe that’s beginning to change….
…The non-lab research model has now become the dominant research model. In my area of research a collection of just five zoos and African sanctuaries recently published more scientific papers in higher impact journals than all five active U.S. chimpanzee laboratories. These non-lab researchers contributed data relevant to fighting HIV, Malaria, Parkinson’s, Autism, Alzheimer’s, and a myriad of other human ailments. They did this while studying chimpanzees that live life freely in extremely enriched environments. …
The Asian Harlequin ladybug, Harmonia axyridis, eats aphids like they’re Popplers, and it’s been repeatedly introduced into the U.S. and Europe to do exactly that. But since it was first introduced, H. axyridis has spread of its own accord, and displaced native ladybugs. This isn’t just because the Harlequin ladybug eats more aphids, or breeds faster, than the locals; it looks like part of the Harlequin’s success is due to the fact that it eats its native competition….
Life is short, but snakes are long is written by Andrew Durso who is a PhD student at Utah State University, where he studies the behavior, physiology, and ecology of toad-eating snakes. So, everything on his blog is about snakes. And every post on his blog has something about snakes that you have not known before.
If the pictures of those towering wildfires in Colorado haven’t convinced you, or the size of your AC bill this summer, here are some hard numbers about climate change: June broke or tied 3,215 high-temperature records across the United States. That followed the warmest May on record for the Northern Hemisphere – the 327th consecutive month in which the temperature of the entire globe exceeded the 20th-century average, the odds of which occurring by simple chance were 3.7 x 10-99, a number considerably larger than the number of stars in the universe…
There’s something fascinating about our chromosomes. We have 23 pairs. Chimpanzees and gorillas, our closest living relatives, have 24. If you come to these facts cold, you might think this represented an existential crisis for evolutionary biologists. If we do indeed descend from a common ancestor with great apes, then our ancestors must have lost a pair after our lineage branched off, some six million years ago. How on Earth could we just give up an entire chromosome….
Your doctor doesn’t like what’s going on with your blood pressure. You’ve been taking medication for it, but he wants to put you on a new drug, and you’re fine with that. Then he leans in close and says in his most reassuring, man-to-man voice, “I should tell you that a small number of my patients have experienced some minor sexual dysfunction on this drug. It’s nothing to be ashamed of, and the good news is that this side effect is totally reversible. If you have any ‘issues’ in the bedroom, don’t hesitate to call, and we’ll switch you to another type of drug called an ACE inhibitor.” OK, you say, you’ll keep that in mind…..
Like so many other skeptics, I just returned from TAM, which, despite all the conflict and drama surrounding it this year, actually turned out to be a highly enjoyable experience for myself and most people I talked to. As I’ve been doing the last few years, I joined up with Steve Novella and other proponents of science-based medicine to do a workshop about how difficult it is to find decent health information on the Internet, and how the “University of Google” all too frequently puts quackery on the same level as reliable sources of medical information because all that matters for most search engines when it comes to ranking search results is the number and kinds of sites that link to a given site…..
Running scientific experiments is, frankly, a pain in the ass. Sure, it’s incredibly satisfying when days or weeks of hard work produce a clean-looking result that’s easy to interpret. But often as not, experiments simply fail for no obvious reason. Even when they work, the results often leave you scratching your head, wondering “what in the world is that supposed to tell me?” The simplest solution to these problems is obvious: don’t do experiments….
Imagine a molecule that underlies the virtues that glue societies together. Imagine that it brought out the better angels of our nature with just a sniff and could “rebond our troubled world.” Imagine that it was the “source of love and prosperity” and explained “what makes us good and evil.” Well, carry on imagining. This is a story about oxytocin, and oxytocin is not that molecule….
If a penguin falls in the forest and no one is there to hear it, I don’t know what kind of forest that is—but everyone who’s interested in penguins is probably hanging out a lot closer to the South Pole. The charismatic birds let scientists and tourists alike get a close look without too much trouble. And all that familiarity has the potential to change penguins, and other closely watched animals, for good….
This ultimate cat fight has happened more times than you might expect. The Romans pitted African lions against Asian tigers in the Coliseum, to the rip-roaring pleasure of the Plebeians. A few fights were also staged in the early decades of the 20th century, and on several modern occasions, accidental cross-species encounters at zoos have quickly developed into gruesome scenes guaranteed to scar any nearby schoolchildren for life. But how do these lion versus tiger showdowns go down?…
Unlike most sites where the business of cosmology is done, Fermi National Accelerator Laboratory—known colloquially as Fermilab—isn’t in a remote spot. The facility is in Batavia, Illinois, part of the sprawling metroplex of Chicago, and it’s just a short drive from two major tollways. The Standard Model describes a plethora of particles, but it has nothing on the number of fast-food joints and auto shops within ten minutes’ drive of the Fermilab gates. My friend hosting me during my stay in Illinois wasn’t even aware of the lab’s location, despite having friends living close by—the area around it is that dense…
The modern dancer and choreographer Merce Cunningham died in 2009, and his company gave its final performance at the end of last year. Many of his dances will live on in the memories of former company members who go on to restage them. But there’s one solo, “Loops,” that Cunningham never taught to another dancer. This piece lives on through a different medium: digital motion capture…
Contagions is a blog written by Michelle Ziegler (Twitter, Facebook, the other two blogs by Michelle – Heavenfield and Selah – are focused entirely on history and not on medicine or science). In Contagions, Michelle explores infectious disease – there is a lot about the Plague – from history to epidemiology to most recent scientific papers. Sometimes gruesome, always fascinating.
In March the US Centers for Disease Control and Prevention (CDC) the newly measured autism prevalences for 8-year-olds in the United States, and headlines roared about a “1 in 88 autism epidemic.” The fear-mongering has led some enterprising folk to latch onto our nation’s growing chemophobia and link the rise in autism to “toxins” or other alleged insults, and some to sell their research, books, and “cures.” On the other hand, some researchers say that what we’re really seeing is likely the upshot of more awareness about autism and ever-shifting diagnostic categories and criteria….
A migrating robin can keep a straight course even when it flies through a cloudy night sky, devoid of obvious landmarks. That’s because it can sense the Earth’s magnetic field. Something in its body acts as a living compass, giving it a sense of direction and position. This ability – known as magnetoreception – isn’t unique to robins. It’s been found in many other birds, sharks and rays, salmon and trout, turtles, bats, ants and bees, and possibly cows, deer and foxes. But despite more than 50 years of research, the details of the magnetic sense are still elusive….
There are still a lot of elbows being thrown in the squabble about “creation” versus “curation,” and it seems to be getting worse. As humans tend to do, we’re talking past each other and pretending to simplicity in the face of the complex and the weird. Here’s what I think is going on. I think we’re getting tripped up by two things: clumsy language and a misapprehension about competition for limited resources….
This morning I was reading a newly published paper that I found intriguing, not only for its content1 but also for who it cited — sort of. Among the regular cadre of peer-reviewed journal articles supporting the author’s findings were two blog posts by University of Glasgow professor Roderic Page. Rod is a major proponent for digitizing and linking biodiversity literature with all aspects of a species’ pixel-trail across the internet, so I was excited to see his blog being “formally” recognized. As I finished reading the paper and reached the References section, I skimmed through to see how a blog citation might be formatted. Much to my dismay, after breezing through the L’s, M’s, and N’s I found myself within the R’s, with nary a Page in sight…
…I’ve been working with a great new group, the Food and Environment Reporting Network — one of the grant-funded journalism organizations that have arisen in the wake of the collapse of mainstream journalism — on an important, under-reported topic. Which is: Over the past decade, a group of researchers in several countries have been uncovering links between the use of antibiotics in chicken production and the rising occurrence of resistance in one of the most common bacterial infections in the world. The infection in question is UTI, which just about every woman I know will recognize: It stands for urinary tract infection, and on average one out of every 9 women in the United States suffers one at least once per year. There are 6 million to 8 million UTIs in the US each year, costing at least $1 billion in healthcare spending….
Robin Dunbar may not be a household name, but some of his thinking has reached the status of household ideas. You’ve heard that 150 is an approximate upper limit on the number of our family-and-friend relationships because that’s how many connections we can track? That’s Dunbar. You’ve read the theory that language evolved as a sort of replacement for hands-on grooming among our primate relatives when group size got big? That’s Dunbar too. Now, in The Science of Love and Betrayal, Dunbar, who is Professor of Evolutionary Anthropology at Oxford, asks seductive questions about love and friendship. Why do men and women pair-bond when so many other animals don’t? How do biology and sociality intersect in explaining human attraction to others? …
The recent news of Dirk Smeesters’ resignation is certainly not good news for social psychology, particularly so soon after the Diedrik Stapel case, but I believe it can serve as an opportunity for the field to take important steps towards reform. The reforms that are needed the most, however, are not restricted to preventing or detecting the few instances of fraud by unscrupulous researchers who are intentionally falsifying data. What we should be more concerned about are the far less egregious, but much more common offenses that many of us commit, often unknowingly or unintentionally, and almost never with fraudulent intent….
It seems like every spring there is renewed coverage of a partial skeleton that was found on the island of Lazaretto Nuovo (one of two 15th-16th century leper colonies near Venice) in 2009. I’ve never covered it here, but since I was alerted to an airing of a documentary about the skeleton on Italian TV this week, I thought it may be time to track the progress of the so-called Vampire of Venice (“il vampiro di Venezia” in Italian, and not to be confused with a similarly named Dr. Who episode)….
Our experiences help shape our brains. So it might make sense that for a person born without hearing, the part of the brain that’s meant to process audio would be underdeveloped. But according to a new study, those who have been deaf since birth actually use the sound-related part of the brain — known as the primary auditory cortex — to do even more heavy lifting than their hearing counterparts. …
Musings of a Dinosaur is a blog written by a physician, family practitioner, Lucy E. Hornstein, author of the book Declarations of a Dinosaur: 10 Laws I’ve Learned as a Family Doctor. Having a small general family practice is different from beeing a specialist in a large hospital. Approach to patients is different. The way one runs the business is different. The thoughts about electronic medical records (a frequent topic of the blog) are different. A valuable perspective, wry and funny and insightful.
At any temperature above absolute zero, particles in a system move randomly, an effect known as thermal fluctuation. The random character of the fluctuations means they cannot be put to work in a mechanical sense (the measure of the energy unavailable for work is called entropy). 19th century physicist James Clerk Maxwell proposed a tiny intelligent “demon” that could harvest the thermal fluctuations to restore their usefulness; later work in the 20th century showed that the demon itself would have entropy, which would keep the thermodynamic books balanced.
I pull up a test result for my patient, and the senior resident standing behind me lets out an excited squeal. “I’ve never seen the imaging come back positive for this,” she says. Our two-week-old infant, who already has a rare infection, also has a rare associated structural abnormality. It’s not benign, but it is fixable. The fix usually requires surgery. As we walk over to the patient’s room to update her mother, my senior gushes about the zebra that was uncovered on the ultrasound. She asks me if I’m excited. “I dunno,” I mutter, which is somewhat more diplomatic than my disgust that she is. ”Her kid has to get surgery now.”
…Even though flies as a group aren’t exactly giants, the new species was around half the size of the previous smallest species. Brown named it Euryplatea nanaknihali after Nanak Nihal Weiss, a young boy from Brown’s home town in Los Angeles. Weiss is an entomology fanatic and Brown hopes that the name will help to keep his interest for years to come….
Several of the regular readers of this column have told me that since I’ve been brave enough to tell the truth about evolution, I should do the same for climate change and expose it as a hoax. In one case I replied that in my stories I always strive to reflect the truth to the best of my abilities. He wrote that he was “disappointed.” These evolution-accepting climate change “skeptics” are an interesting breed, revealing some key differences in the ways they and creationists approach science. Self-described climate skeptics are much more scattered in their views than are creationists, but they are better organized and together speak with a louder, and angrier voice….
In April of this year, I headed out to a marl pit in Clayton, New Jersey to watch a team of Drexel University students and their teacher, Professor Kenneth Lacovara, dig for fossils. Marl, a lime-rich mud, had been mined and used as the 19th century’s leading fertilizer, but since around World War II (with the development of more advanced, synthetic fertilizers), demand for it has steeply lessened, and there aren’t many marl mining businesses left in the US. The marl pits of Southern New Jersey are famous for something else, though: they have been incredibly rich in fossil finds. In February, Dr. Lacovara had announced that the Paleontology department at Drexel would team up with the Engineering department for what would largely be a novel new project: scanning all of the fossils in the University’s collection (including some previously unidentified dinosaurs of Lacovara’s own finds in other parts of the world) using a 3D scanner. The Engineering department would then take those scans and use a 3D printer to create 1/10 scale models of the most important bones. But, he reported, that wouldn’t be the end of it: they intended, he said, to use those scale polymer “printouts” to model and then engineer fully working limbs, complete with musculature — to create, in effect, a fully accurate robotic dinosaur leg or arm, and eventually, a complete dinosaur….
Basically since we started walking upright, childbirth has been difficult for women. Evolution selected for larger and larger brains in our hominin ancestors such that today our newborns have heads roughly 102% the size of the mother’s pelvic inlet width (Rosenberg 1992). Yes, you read that right. Our babies’ heads are actually two percent larger than our skeletal anatomy…
For years self-help gurus have preached the same simple mantra: if you want to improve your life then you need to change how you think. Force yourself to have positive thoughts and you will become happier. Visualise your dream self and you will enjoy increased success. Think like a millionaire and you will magically grow rich. In principle, this idea sounds perfectly reasonable. However, in practice it often proves ineffective….
A recent issue of Nature had an interesting article on what seems to be a wholly paradoxical feature of models used in climate science; as the models are becoming increasingly realistic, they are also becoming less accurate and predictive because of growing uncertainties. I can only imagine this to be an excruciatingly painful fact for climate modelers who seem to be facing the equivalent of the Heisenberg uncertainty principle for their field. It’s an especially worrisome time to deal with such issues since the modelers need to include their predictions in the next IPCC report on climate change which is due to be published next year….
A key component of classical sexual selection theory is the idea that males maximize their evolutionary fitness—the number of children they ultimately have—by mating with lots of females, while females maximize their fitness by selecting only one or a few high-quality partners. It’s pretty clear that this model works well for some species (like ducks), but also that there are many it doesn’t fit so well. Now it looks like one of the “classic” experimental examples of sexual selection may actually fall into the latter category….
….Like all major new technologies, the Internet has a good side and a bad side. In many cases, the same property is both good and bad, and one place that this is particularly true is in medical information. The Internet has an abundance of medical information, all there for the reading and learning, and various discussion forums that began with online BBS services and the now mostly obsolete global discussion community of Usenet allow people from all over the world who would never have communicated directly with each other before to share information and experiences. Unfortunately, there is a dark side to this. Regular readers of this blog know what that dark side is, too. The same technology that allows reputable scientists and doctors to publish reliable medical information to the world at very low cost also allows quacks and cranks to spew their misinformation, nonsense, pseudoscience, and quackery to the whole world at very little cost. And, boy, do they ever! In many ways, the quacks are a far more effective online presence than skeptics and supporters of science-based medicine. I mean, look at SBM itself. We’re still using a generic WordPress template. Now look at an antivaccine website like The International Medical Council on Vaccination or Generation Rescue or the antivaccine blog Age of Autism. Look at quack websites like NaturalNews.com The comparison, at least when it comes to web and blog design, is not flattering…..
Hale County in west central Alabama and Bamberg County in southern South Carolina are 450 miles apart. Both counties have a population of 16,000 of which around 60% are African American. The median households and per capita incomes are well below their respective state’s median, in Hale nearly $10,000 less. Both were named after confederate officers–Stephen Fowler Hale and Francis Marion Bamberg. And although Hale’s county seat is the self-proclaimed Catfish Capitol, pulling catfish out of the Edisto River in Bamberg County is a favorite past time. These two counties share another unique feature. Amidst a blanket of Republican red both Hale and Bamberg voted primarily Democratic in the 2000, 2004, and again in the 2008 presidential elections. Indeed, Hale and Bamberg belong to a belt of counties cutting through the deep south–Mississippi, Alabama, Georgia, South Carolina, and North Carolina–that have voted over 50% Democratic in recent presidential elections. Why? A 100 million year old coastline….
On a bright morning in early June, a Texas rancher named Jerry Abel turned his small herd of cattle out to graze. The 18 cows moved hungrily into that field of fresh grass. Within a few hours, only three were still alive. Abel’s 80 acre ranch sits just a little east of Austin and the story was strange enough that on Sunday a local CBS affiliate picked it up. “There was nothing you could do,” Abel told KEYE about his desperate efforts to save the animals. “Obviously, they were dying.”…
Compared to mounted dinosaur skeletons, fossil footprints might seem like mundane objects. They only record one small part of a fantastic creature, and it is harder to envision a whole dinosaur from the ground up than the wrap flesh around a skeletal frame. But we should not forget that dinosaur footprints are fossilized behavior—stone snapshots of an animal’s life. And sometimes, trackways record dramatic moments in dinosaur lives….
Good news for aspiring jelly-bean jar estimators who are under 30! Your intuitive grasp of numbers may not have peaked yet. Unlike other cognitive skills, the ability to approximate keeps improving well into adulthood. Since the skill is tied to mathematical smarts, this news might bring hope to struggling students….
June 8, 2012, Cedaredge Colorado—It was an ordinary Friday afternoon. I was at my desk writing when I looked out the window and saw an enormous plume of smoke billowing from the back of our property. It was the kind of moment when you’re supposed to remain calm and remember all the wise things you learned in first aid class or girl scouts. (Stop! Drop! Roll!) Instead, I panicked.
The first stage of the Black Death among Europeans was said to begin with the whoosh of a Mongol trebuchet. Gabriele De’ Mussi, a lawyer from near Genoa writing in about 1348, is believed to have recorded the account of the earliest use of plague as weapon of war at Caffa in 1346….
I could write the entire genome of a flu virus in around 100 tweets. It is just 14,000 letters long; for comparison, our genome has over 3 billion letters. This tiny collection of genetic material is enough to kill millions of people. Even though it has been sequenced time and time again, there is still a lot we don’t know about it….
Paul, the lead author, interviewed sheepdog trialer Damian Wilson about his interactions with his dog, a border collie named Yandarra Whiskey. Damian and Whiskey gave Paul a demonstration of the techniques used in sheepdog competitions as they together tried to move a mob of three sheep. In a competition in New South Wales, a trainer and dog have to move three sheep who have never been herded through a difficult obstacle course, and the trainer loses points if he (or, less frequently, she) breaks from a slow, measured pace walking the course. The rules mean that the dog itself must be trained until it anticipates the sheep’s reactions, and understands, on some level, what dog and trainer, together, are trying to accomplish. Although the trialer may give commands, the dog, too, is a kind of expert….
If you missed the final launch of the Space Shuttle, or the first private spacecraft rendezvous with the International Space Station, fear not. A new documentary to be released late this year promises you a fiery, 3-D, launch-pad view of these historic flights…
The Napoleonic Wars brought John Harrison Curtis’ studies to a standstill, as he became one of thousands of young men conscripted to fight against Napoleonic advances towards Britain. With his medical learning in hand, Curtis enlisted in the Royal Navy in 1808, to obtain his qualifications as surgeon and extend his medical skills. Since 1745, the Royal College of Surgeons in London, Edinburgh and Dublin, and the Navy held close associations with each other as the College was responsible for examining naval surgeons for active service. To be admitted as surgeon in the navy, candidates had to obtain a certificate of competence from the College and then be subjected to a two-hour oral examination at Somerset House….
Special topic #1: Getting young journalists and scientists to become savvy on the Web:
Like clockwork, almost every day for more than two years, Tommy Leung and Susan Perkins bring you Parasite of the Day. Sometimes gross, but always fascinating. And considering how most of us don’t pay much attention to parasites these days, there is something cool to learn every single day.
…Of course, we don’t call it an abortion. We call it “a procedure” or a D&C. See, my potential abortion is one of the good abortions. I’m 31 years old. I’m married. These days, I’m pretty well off. I would very much like to stay pregnant right now. In fact, I have just spent the last year—following an earlier miscarriage—trying rather desperately to get pregnant…
Cognitive neuroscience grew out of experimental psychology, which has decades of amazing observations to link psychology and behavior. But with this legacy comes a lot of baggage. Experimental psychologists observed that we have the capacity for memory, attention, emotion, etc. and they sought to piece those phenomena apart. With the advent of neuroimaging techniques, psychologists put people in brain scanners to see where in the brain behaviors “were”. But this is the wrong way of thinking about these concepts.
…This myth of destiny and inevitable triumph of genius is, to me, completely the opposite of what science is. The scientific method leveled the playing field for discovering truth. Anyone could follow the methods and get to the bottom of things, so truth was no longer subject to tricky things like personal revelation….
…The challenge I took on was to convey the gist of my “brutal logic of climate change” post in a reasonably short amount of time, using as little scientific jargon as possible. Just: there is a problem that calls for urgent action. Business-as-usual means disaster. This is all gloom and doom — not even much humor. I know that turns people off or shuts them down. I know people need to feel a sense of hope and efficacy. I know — indeed, have recently been writing — that we need a vision of a sustainable future. But I needed to do my own version of “Danger Will Robinson!” Just to get it on the record…
…The tunes embedded above weren’t written by a composer, but fashioned through natural selection. They are the offspring of DarwinTunes, a program which creates bursts of noise that gradually evolve based on the preferences of thousands of human listeners. After hundreds of generations, tracks that are boring and grating soon morph into tunes that are really quite rhythmic and pleasant (even if they won’t be topping charts any time soon)….
So little is known about the parasites of snakes that we tend to discount them all together, but the ecological and evolutionary interactions between hosts and their parasites can be very strong. This is a story about how two enterprising snake biologists solved a mystery that had been puzzling entomologists for decades…
…To call someone or something a guinea pig may suggest a mere experiment (“Joe Biden was put out as a guinea pig for the White House”), or it can invoke the specter of exploitation (the U.S. Army wanted “to use young men as guinea pigs and throw them away”). The image either describes the scientific process or condemns it. It’s a totem or a scarecrow. What makes this wording more curious is the fact that guinea pigs, real ones, don’t mean much to working scientists. For all their rhetorical importance, the animals scarcely register in the lab…
Last month, I filed my PhD dissertation, bringing to an end an intellectual and personal journey that began seven years ago in the summer of 2005. I know a lot more now than I did then, and I know a lot more about the boundaries of what I don’t know, too. But not only has my knowledge changed—evolution and ecology looks a lot different now than it did seven years ago when I was planning my dissertation research. At some point, and often multiple points, in the process of getting a PhD, everybody wonders whether what they’re doing is already out of date. Some of the transformations in the field I think I could see coming. For instance, it was clear in 2005 that computational power would keep increasing, phylogenetics would be used more and more to ask interesting questions, more and more genomes would be available for analysis, and evolutionary developmental biology was on the rise. It was unfortunately also predictable that it would be possible to study climate change in real time over PhD-length timescales. And although the 2008 global financial crisis didn’t help, it was clear that funding and jobs were going to be more competitive than they had been for our predecessors….
Humans are natural splitters. We have an innate tendency to look at the world and mentally sort everything into different categories, and grades, and entities: this is one thing, that is another; it was this, now it’s that. Our perception of colour is a good example of how our brains automatically split a continuum into discrete boxes. We’ve incorporated our love of classification deep into science, trying to formalise and quantify the dividing lines we want to draw on everything: it’s this when conditions A and B are met, it’s that when we see Y and Z. But nature doesn’t often make it easy for us to draw our sharp dividing lines….
To many – too many – science is something like North Korea. Not only is it impossible to read or understand anything that comes out of that place, there are so many cultural differences that it’s barely worth trying. It’s easier just to let them get on with their lives while you get on with yours; as long as they don’t take our jobs or attack our way of life, we’ll leave them in peace…
Russ Williams is the Director of the North Carolina Zoological Society and, as far as I know, the only “director of a zoo” who blogs. And does he ever – Russ has been blogging up a storm ever since 2005 when Ed Cone taught him how (you may call me The Blogfather, but Ed Cone is the blogfather for many of us in North Carolina). On his blog Russlings, Russ covers plenty – what is new at the N.C.Zoo in Asheboro, what is new in other zoos around the country and the world, what is new in policy and politics of animal conservation, plus cool pictures and videos of wildlife. But where the value really comes up is at the times of natural disasters – Russ is “in the know” and often the first and/or the only person to blog about the status of zoos and aquaria, as well as farm animals, wildlife preserves etc, in the affected areas. During disasters, Russlings is the Go-To place for such coverage.
No one reading this has the slightest fucking clue what “nature” is, and in 1995 fisheries scientist Daniel Pauly proved it. In the paper that introduced the term “shifting baselines,” Pauly described how experts who determined how many fish should be caught often started with whatever the baseline state of the ecosystem was when they started their careers, instead of considering what a fishery might have looked like in the past, when it wasn’t nearly as degraded….
…Nonetheless, like evolution, the dominance of human beings on Spaceship Earth is a profound and terrifying threat to all sorts of traditional worldviews. If Darwin showed us that God is not our author, the Anthropocene shows that He is not our caretaker. There’s no parent to supply us with endless resources and endless room to dispose of our waste. There’s no one to protect us or prevent us from screwing it all up….
Is preserving the general environmental conditions that allowed civilization to flourish—a moderate climate, a rich array of species, rivers that reach the sea—necessary to ensure humanity endures? Or is minimizing alterations to the global environment introduced by human activity—rising levels of CO2 from fossil-fuel burning, widespread extinction, dams that impound water—more important to our success? Choosing the right approach is vital as the scale of human impact on the planet becomes so large that scientists are calling this new epoch in Earth’s history the Anthropocene (when human activity alters global climate and ecosystems)…
Last week I wrote about the anti-science campaign being waged by opponents of the use of genetically modified organisms in agriculture. In that post, I promised to address a series of questions/fears about GMOs that seem to underly peoples’ objections to the technology. I’m not going to try to make this a comprehensive reference site about GMOs and the literature on their use and safety (I’m compiling some good general resources here.) I want to say a few things about myself too…
Based on the NC legislature’s decree about the science of sea level rise projections and some of the related propaganda we have seen from climate change deniers, I get the sense there is a lot of confusion about sea level rise. So here is a primer on what we know about sea level and climate change…
The Rev. Thomas Long doesn’t have neighbors on Montrose Avenue anymore. Everyone is gone. Widespread chemical contamination from a Monsanto plant was discovered in this quiet city in the Appalachian foothills back in the 1990s. In West Anniston, behind Long’s home, a church was fenced off, and men in “moon suits” cleaned the site for weeks. Nearby, boarded windows and sunken porches hang from abandoned shotgun houses. Stray dogs roam the narrow streets. A red “nuisance” sign peeks above the un-mowed lawn of one empty house. Bulldozers will be here soon…
Jessica Sanchez sits on the edge of her seat in her mother’s kitchen, hands resting on her bulging belly. Eight months pregnant, she’s excited about the imminent birth of her son. But she’s scared too. A few feet away, her mother, Bertha Dias, scrubs potatoes with water she bought from a vending machine. She won’t use the tap water because it’s contaminated with nitrates…
Lately, I’ve got colors on the brain. In part I of this post I talked about the common roads that different cultures travel down as they name the colors in their world. And I came across the idea that color names are, in some sense, culturally universal. The way that languages carve up the visual spectrum isn’t arbitrary. Different cultures with independent histories often end up with the same colors in their vocabulary. Of course, the word that they use for red might be quite different – red, rouge, laal, whatever. Yet the concept of redness, that vivid region of the visual spectrum that we associate with fire, strawberries, blood or ketchup, is something that most cultures share….
The chickens that saved Western civilization were discovered, according to legend, by the side of a road in Greece in the first decade of the fifth century B.C. The Athenian general Themistocles, on his way to confront the invading Persian forces, stopped to watch two cocks fighting and summoned his troops, saying: “Behold, these do not fight for their household gods, for the monuments of their ancestors, for glory, for liberty or the safety of their children, but only because one will not give way to the other.” The tale does not describe what happened to the loser, nor explain why the soldiers found this display of instinctive aggression inspirational rather than pointless and depressing. But history records that the Greeks, thus heartened, went on to repel the invaders, preserving the civilization that today honors those same creatures by breading, frying and dipping them into one’s choice of sauce. The descendants of those roosters might well think—if they were capable of such profound thought—that their ancient forebears have a lot to answer for….
It was the sight of a young male Adélie penguin attempting to have sex with a dead female that particularly unnerved George Murray Levick, a scientist with the 1910-13 Scott Antarctic Expedition. No such observation had ever been recorded before, as far as he knew, and Levick, a typical Edwardian Englishman, was horrified. Blizzards and freezing cold were one thing. Penguin perversion was another….
Curious Experiments by Archbishop Marsh’s Library. “‘Curious Experiments’ for ‘The Amusement and Entertainment of Ladies, as well as Gentlemen’ which took place before a paying audience in Dublin in 1743.” recreated by high school students 270 years later.
Wow – this was hard! I could have had at least Top 20 instead of Top 10 (but you’ll find them all listed down there anyway)…
Blog of the Week:
Tanya Khovanova’s Math Blog is a blog by Tanya Khovanova, a Visiting Scholar and Research Affiliate at MIT, a 1976 gold medalist (and 1975 silver medalist) at the International Mathematics Olympiad. What she does the most (though there is occasionally other stuff there) is to pose difficult (and some not to so difficult) mathematical problems and puzzles for her readers to try to solve in the comments. Go ahead and give it a try yourself!
Although only two years old and previously unrecognized by the scientific establishment, Global Draining (GD) has now become a widely accepted theory. GD states that sea level is falling not rising (Southern Fried Science, 2010a). Current rates of GD indicate the entire world’s ocean will be empty by 2026 (Southern Fried Science, 2010a). Local-scale observation of in situ draining combined with a robust theoretical model firmly place the rate of draining at 40 Gigatons of water per year (Dr. M, 2010). It has been argued that both one and multiple holes occur in the ocean floor that allow for GD (i.e. the monoclavis versus polyclavis hypotheses via McCay, 2010; Southern Fried Science, 2010b). However, the impacts and causes of GD are not clearly understood. Despite this, GD is a fundamental tenet of nearly every facet of science and likely correlated with many aspects of biology, economics, sociology, religion, and politics. For example, GD is likely to lead to massive die offs of sharks and reduce global atmospheric oxygen levels (Shark Diver, 2010)…
In Japan, people often refer to traffic lights as being blue in color. And this is a bit odd, because the traffic signal indicating ‘go’ in Japan is just as green as it is anywhere else in the world. So why is the color getting lost in translation? This visual conundrum has its roots in the history of language…
My first child was born just about nine months ago. From the hospital window on that memorable day, I could see that it was surprisingly sunny for a Berkeley autumn afternoon. At the time, I’d only slept about three of the last 38 hours. My mind was making up for the missing haze that usually fills the Berkeley sky. Despite my cloudy state, I can easily recall those moments following my first afternoon laying with my newborn son. In those minutes, he cleared my mind better than the sun had cleared the Berkeley skies…
Of all the noises that my children will not understand, the one that is nearest to my heart is not from a song or a television show or a jingle. It’s the sound of a modem connecting with another modem across the repurposed telephone infrastructure. It was the noise of being part of the beginning of the Internet…
Is it a paradox to hate your own species? Is such a feeling the product of a broken and conflicted mind? Or could it perhaps be the signature of psychopathy? Every day these questions run through my mind and I feel guilty. Why? Well, because I do hate my own species. Homo sapiens is terrible, and I’m surprised more people don’t recognise this…
…In January 2000, the mass media ran several stories about Robert Smith, a surgeon at the Falkirk and District Royal Infirmary who had amputated the legs of two patients at their own request and was planning a third amputation. The news stories incorrectly described the patients as suffering from Body Dysmorphic Disorder. They further stated that the director of NHS trust running the hospital at which Smith works described the amputation of healthy limbs as “inappropriate”; since then, no British hospital has performed a voluntary amputation…
…I suppose one could hook up the computers directly to the experiments and have them generate models, test the models against new observations and then modify the experimental apparatus without any human intervention. However, I am not sure that would be science. Science is ultimately a human activity and the models we produce are products of the human mind. It is not enough that the computer knows the answer. We want to have some feeling for the results, to understand them. Without the simple models, Mickey Mouse science, that would not be possible: the big news made ever so small…
In popular culture, paleontologists are like Indiana Jones. Rugged men wandering through rocky deserts, wearing wide-brimmed leather hats and multi-pocketed khaki vests. Rock-hammers hang nonchalantly from their belt-loops, maps and note-pads protrude from pockets. On a whim, they brush aside some sand to reveal a ferocious skull and massive vertebrae, and then they puzzle out the mysteries of dinosaurs just by staring at the rocks. But in contemporary science, paleontologists are biologists, computer programmers, and engineers…
Special topic: Scientists, Journalism and Outreach
Wi-Fi and Amtrak: Missed Connections by Ron Nixon – obviously written by someone who’s never boarded anything but Acela, which is notorious for bad wifi. I find wifi perfectly usable on the Carolinian route of Amtrak.
Vintage Space is a blog by Amy Shira Teitel, science writer and historian of space exploration living in Arizona. She has been busy lately, contributing articles to Discovery News, Motherboard, Spaceflight Observer podcasts, Scientific American Guest Blog, Soapbox Science blog, Timeline Magazine, AmericaSpace and Universe Today, among else. Vintage Space is her writing laboratory, where she first explores topics she may subsequently expand into longer pieces for other venues. And she links to all of her articles as they go live in various places so you can keep up with her prolific output. Those of you regular readers of Scientific American blogs may remember her guest posts, and for those of you not familiar, those can give you the taste of her fascinating forays into the history of space: Sky Crane – how to land Curiosity on the surface of Mars and Apollo 1: The Fire That Shocked NASA and John Glenn: The Man Behind the Hero.
The 1850 murder of Gustave Fougnies in Belgium is not famous because of the cleverness of his killers. Not at all. They – his sister and brother-in-law – practically set off signal flares announcing their parts in a suspicious death.
It’s not famous because it was such a classic high society murder. The killers were the dashing, expensive, and deeply indebted Comte and Countess de Bocarmé. The death occurred during a dangerously intimate dinner at their chateau, a 18th century mansion on an estate in southern Belgium.
Nor it is remembered because the Comte died by guillotine in 1851 – so many did after all.
No, this is a famous murder because of its use of a notably lethal poison. And because the solving of this particular murder changed the history of toxicology, helped lay the foundation for modern forensic science. The poison, by the way, was the plant alkaloid nicotine….
…I mean Dawkins and Wilson no disrespect by calling them two among many. I trust that they would agree and would defer to others especially when it comes to mathematical models, which is not their area of expertise. If the public is going to become literate on the issues at stake—as well they should, because they are fundamental to the study of human sociality—then they will need to realize that both Wilson and Dawkins get some things right and other things wrong. Moreover, the entire community of scientists is in more agreement than the infamous exchange in Nature seems to indicate. Taking the argument from authority seriously can lead to a breakthrough in the public’s understanding of social evolution. …
…Dose-specific toxicity is indeed of paramount importance in medicine, but if you delve deeper, the common mechanism underlying the toxicity of many drugs often has less to do with the specific drugs themselves and more to do with the other major player in the interaction of drugs with the human body – proteins. Unwarranted dosages of drugs are certainly dangerous, but even in these cases the effect is often mediated by specific proteins. Thus in this post, I want to take a slightly different tack and want to reinforce the idea that when it comes to drugs it’s often wise to remember that “the protein makes the poison”. I want to reinforce the fact that toxicity is often a function of multiple entities and not just one. In fact this concept underlies most of the side-effects of drugs, manifested in all those ominous sounding warnings delivered in rapid fire intonations in otherwise soothing drug commercials…
Neuroscientists have long been banging their heads on their desks over exaggerated reports of brain scanning studies. Media stories illustrated with coloured scans, supposedly showing how the brain works, are now a standard part of the science pages and some people find them so convincing that they are touted as ways of designing education for our children, evaluating the effectiveness of marketing campaigns and testing potential recruits…
Invisibility cloaks aren’t just for Harry Potter anymore. Last year, researchers made one that cloaked things in time. Now they’ve made thousands of tiny invisibility cloaks that trap a rainbow. That’s right, 25,000 invisibility cloaks trapping a rainbow. The first question you might be asking is: why? Why does it take 25,000 invisibility cloaks to trap a rainbow? Or maybe, why trap a rainbow in the first place?
You have no idea how long I have been planning to look at the blasters in Star Wars. No idea. Finally, the 35th Anniversary of Star Wars has motivated me to complete my study (which I haven’t actually started). Here is the deal: What are these blasters? How fast are the blaster bolts? Do the blasters from the spacecraft travel at about the same speed as the handheld blasters? Why do people still think these are lasers?…
What does it mean to be a good role? Am I a good role model? Playing around with kids at home or in the middle of a science classroom, adults often ask themselves these questions, especially when it comes to girls and science. But despite having asked them many times myself, I don’t think they’re the right questions…
A Biologist went down to the coffee shop one day, because the walk out to the edge of the University campus provided some brief respite from the laboratory. Along the way the Biologist encountered an Evolutionary Psychologist, who was also going to the coffee shop, and they fell to walking together…
When I was a kid – and who am I kidding; when I was an adult too – I made fun of the science in movies. “That’s so fakey!” I would cry out loud when a spaceship roared past, or a slimy alien stalked our heroes. Eventually, my verbal exclamations evolved into written ones. Not long after creating my first website (back in the Dark Internet Ages of 1997) I decided it would be fun to critique the science of movies, and I dove in with both glee and fervor. No movie was safe, from Armageddon to Austin Powers…
Stegosaurus is undoubtedly one of the most perplexing dinosaurs. What was all that iconic armor for? (And how did amorous stegosaurs get around that complication?) Paleontologists have been investigating and debating the function of Stegosaurus ornamentation for decades, but without much consensus. The dinosaur’s spectacular plates were certainly prominent visual signals, but could they also have been used for regulating body temperature? Or might there be some evolutionary impetus we’re not thinking of?
Lost in your brain by David Dobbs – “When science writer David Dobbs is suddenly unable to remember how to drive his kids to school, he sets off on a quest to understand his own brain, and makes a shocking discovery.”
Posted onJune 1, 2012byBora Zivkovic|Comments Off on Live chat today at noon about science blogging, circadian rhythms, sleep, metabolism and evolution
Join Robin Lloyd and myself today at 12 noon EDT for the first edition of the Scientific American Fast Chat. Log in and ask questions, and we’ll try to answer. The whole thing will last about 30 minutes.
I am not sure how this stuff happens, but there was a flurry of new papers in the circadian field just preceding the event. Several of them have already received quite a lot of attention in both old and new media, and rightfully so, but I decided not to cover them one at a time just as the embargo lifted for each one of them.
Instead, I will just very briefly describe and explain the main take-home messages of each one of them, link to the best coverage for those who want more detail (“Cover what you do best. Link to the rest.“), and then try to come up with more of a ‘big picture’ summary of the current state of the field.
I apologize in advance for covering and linking to some of the papers that are not published in Open Access journals. I am not as strict about this policy as some other bloggers are (“if my readers cannot access it, they cannot fact-check me”), and will occasionally cover non-OA papers. Even if most of my readers cannot access them, I gather that a miniscule proportion can access and, if I got something wrong, can alert the other readers in the comments. And speaking of Open Access, I am not one to sign many online petitions, but this one is worth it so please sign if you have not done it already.
So, let’s see what new and exciting in chronobiology these days…
What is it about: Robustness of daily rhythms and their flexible, adaptive responses to the environment, require a feedback loop between a cluster of clock cells in the brain and another cluster of non-clock cells in the brain of Drosophila melanogaster.
What is new: Feedback loops between two or more brain centers (or tissues, or organs) as necessary for either existence of some circadian rhythms, or for the rhythms’ robustness and fine-tuned response to the environment, have been studied mostly in vertebrates, especially birds and lizards, and to some extent mammals. Such feedback loops have been found in the fruitfly as well. This paper finds out a lot of detail about this feedback loop, including the use of glutamate as a neurotransmitter in one half of the loop. As Drosophila is still the lab organism with the most developed techniques for precise genetic manipulations, this is an important advance.
Take-home message: How core clock genes turn each other on and off within a cell over 24 hours is just the beginning, a small part of the story. To work properly, to be adaptive, and to respond well to environmental cues, circadian rhythms require organization at a higher level, with fine-tuned communication among clock-cells and between clock and non-clock tissues.
Some more thoughts: This is a technical tour-de-force. Fruitfly genetics techniques today are so powerful and this paper appears to use them all: inserting, deleting, downregulating and upregulating genes of choice in precisely targeted cells in the brain. As every behavioral biologist knows, once introduced into an experiment animals do whatever the heck they please. The behavior measured in this paper was a simple light-avoidance test – fruitfly larvae (and in the last experiment, also adults) are placed in a petri dish that is half in light, half in darkness, and the movement and position of the larvae is monitored. Considering how messy such behavioral data tend to be, the results in this paper are quite impressive.
The Abstract/Summary, the Introduction, and the (far too short) Discussion are very clear, straighforward and easy to read and understand. They are also upfront and direct about their main take-home message. The many pages in-between, though, are clearly meant to be read only by Drosophila clock geneticists who can actually wade through the essentially endless litany of acronyms in hope of replicating or following up on this study. Clocks are my field, but I am not a geneticist or drosophilist, so much of the Materials & Methods and Results sections in this paper are over my head. Maddeningly, some of the most important stuff is hidden in the Supplemental Materials, including this model for how the whole thing works (shouldn’t this image be up front, on the top of the whole thing?):
Drosophila neuron model
Note: If I remained in research, I would have done something like this, not necessarily in fruitflies, but definitely looking at neural networks, feedback loops and higher-level organization of the circadian system, within ecological and evolutionary contexts. This may bias me toward liking this paper as much as I do.
Good coverage elsewhere: None that I can find. Only a warmed-up (and not that good) press release at Futurity and ScienceDaily.
What is it about: A protein (peroxiredoxin) that is found in almost all living organisms has two states/conformations that cycle at approximately 24 hours. Presence and proper function of core circadian clock genes is not necessary for the cycling of this protein. An Archea species that does not live on the surface does not have the clock and does not have this protein.
What is new: This finding in human red blood cells and a Protist (O.tauri) was published last year. This paper adds similar data for a whole bunch of other organisms: cyanobacteria, archaea, fungi, plants, insects and vertebrates.
Take-home message: There are really two take-home messages, one physiological, one evolutionary. First, this demonstrates that circadian clocks are properties of the entire cells (or assemblages of cells in case of multicellular organisms), not just the transcription/translation loops of core clock genes.
Second, the protein in question, the peroxiredoxin, could be akin to “scaffolding”, something that allows a cell to keep cycling while genes come and go, mutate and change and duplicate, while being fine-tuned by natural selection. Over billions of years, this can result in major groups of organisms (e.g., animals vs. plants vs. fungi vs. bacteria, vs. several different groups of protists) having entirely different circadian genes, yet all of them using the same “logic” (transcription/translation feedback loops).
Both the peroxiredoxins and the circadian clocks are thought to have originated as defense from UV radiation of the early oceanic surfaces (Pittendrigh, C.S., 1967. Circadian rhythms, space research, and manned space flight. In: Life Sciences and Space Research 5:122-134. North-Holland, Amsterdam.), or defense against other kinds of demage, including that from oxidation, so it makes sense that they co-originated and co-evolved only once in the history of the planet, perhaps around 2.5 million years ago when photosynthetis bacteria introduced lots of molecular oxygen into the Earth’s atmosphere. It also makes sense that they both are missing in organisms that have never lived close to the oceanic or terrestrial surface (e.g., many Archaea).
Essential reading: When the two papers (on red blood cells and the protists) came out last year, I wrote a very comprehensive post that places this research direction into historical, philosophical, methodological and even media context. There is not much in that post that would change with the publication of this new paper apart from additional confirmation in several new species. So just go and read it again.
Some more thoughts: Peroxiredoxins cycle in all kinds of different cells with an approximately 24 hour period. This makes them, almost by definition, circadian clocks. Last year’s papers also show that the peroxiredoxin clock dominates its phase over the clock driven by core circadian genes. But there is something still to find out, and it is important: can the peroxiredoxin clock drive any other rhythms? For it to work as a biological pacemaker, it is not sufficient for it to cycle itself, it also need to drive timing of other events in the cell (and the entire organism). I am assuming that this research group will look at this problem next.
Mammals have six peroxiredoxin genes. In an experiment (Zhang et al., Cell , 2009), human cell lines were engineered in such a way that each culture had a different peroxiredoxin gene knocked out. None of the knock-outs had any effect on the regular circadian expression of the core clock gene Bmal1. Of course, having six genes indicates redundancy in function. One would need to knock out all six simultaneously in order to see an effect on other rhythms in the cell, but there is a question if cells with all peroxiredoxins knocked out can survive at all. Someone should try this.
Also, that experiment was done in mammalian cells. Mammals are probably the worst model system for studying this question. Vertebrates have undergone several events of gene (and genome) duplication, and mammals got at least another one. If you look at mammals, every clock gene exists in multiples (e.g,. Per1, Per2, Per3). Poor peroxiredoxin probably cannot do much in such a massively genetically determined system.
Gene duplication allows for evolutionary experimentation. As long as one copy of the gene keeps working, the others are free to mutate. Some mutations will be selected against (e.g., if they mess up the clock function) and others will be selected for (e.g., if they fine-tune the circadian function, making it more flexible and adaptable, or start performing some other valuable function instead). This means that functions formerly in the domain of higher-level organization or the domain of phenotypic plasticity, are now under control of genes. This process is called Genetic assimilation (and sometimes Baldwin effect, though that term is usually reserved for genetic assimilation of learned behaviors). So it is quite possible that the clock in mammals is over-determined by genes, making it useless for the study of peroxiredoxins as scaffolding for circadian evolution.
If I was doing this research, I would stay away from these vertebrate oddballs for at least the next five or ten years, and focus my time, funds and energy on the study of bacteria, archaea, protists, fungi and perhaps some plants – smaller the genome the better.
What is it about: In barley cultivars from Northern Europe a mutation in a gene responsible for flowering feeds back on the circadian clock genes, greatly reducing the amplitude of the gene cycling, effectively shutting down the clock. Without proper clock function, barley does not use the clock to measure seasonal changes in daylength (photoperiodism) but instead matures at the fastest rate its development permits. This allows barley to mature and flower early in the season, as well as to photosynthetise throughout the long days of summer in the North.
What is new: Yet another organism in which some of the clock function is temporarily or permanently eliminated. Good news: unlike the other such organisms which tend to be not-well-studied inhabitants of extreme environments, barley is a domesticated plant, well researched and easy to use in the lab.
Take-home message: one has to be careful with interpreting studies like these – just because an organism does not show a couple of well-studied rhythms in physiology and behavior, and does not show cycling in expression of core clock genes does not mean that all circadian function is gone. Ensembles of cells, or feedback loops between tissues, or cytoplasmic factors like peroxiredoxin may still be working in the organism, it’s just that this cannot be detected with the techniques used in the study.
What is it about: Female mice kept in 24 cycles get and remain pregnant easily. Female mice kept in rotating shifts (either advances or delays of the 24 hour cycle by 6 hours every several days) do not. Difference is striking!
What is new: Interactions between circadian rhythms and reproductive cycles have been studied for decades in many different organisms. Last year, a study with already pregnant mice moved to rotating shifts did not result in spontaneous losses of pregnancy. This study suggests that rotating shifts prevent pregnancy to begin in the first place, probably by interfering with implantation of the egg in the uterus.
Take-home message: Another example how clock is not just about timing of downstream events, but also plays part in them more directly. While this study was done in rodents, it works well together with epidemiological data from humans working on rotating shifts. As the light-dark cycle is shifted, the brain clock resets itself pretty quickly, over a period of a couple of days. But peripheral clocks in all the other organs will reset slower, each at its own rate. This include the ovaries, uterus etc, which may not be ready for egg implantation at the time of day when the brain send the relevant signal. In essence, internal desynchronization of clocks prevents all the parts of the system to work in synchrony – this is the main negative effect of jet-lag, and it applies to reproduction as much as it does to digestion and other functions.
Effect of entrainment on success of pregnancy
Some more thoughts: Both the paper and the media coverage are clear, straightforward and readable. But if one wanted to explain these data by building a formal/conceptual or mathematical model this could easily get mind-bogglingly complicated: one would have to take into account multiple feedback loops between repeatedly desynchronized oscillators, plus potential effects of photoperiodism.
Good coverage elsewhere:Sarah Fecht did a great job. Most of the rest of the media just regurgitated the press release. Oh, this was even covered by Daily Mail 😉
What is it about: A large-scale study of Danish female soldiers found a higher incidence of breast cancer in those who had to work night shifts. Longer the period of night-shift work, greater the incidence. Also, early risers were more susceptible to this negative effect of night shift work.
What is new: Earlier studies were mostly done in nurses in the USA. This provides a much larger data-set of women followed over a long period of time in a different profession in a different country. Military environment also controls for many other aspects of life (food, quality of medical care, physical fitness, etc.) which tends to be more uniform than in the general population.
Take-home message: Prolonged night shift work, especially if you are an early bird, may be bad for your health.
Some more thoughts: Internal desynchronization between various body clocks, especially long-term, is bound to have negative consequences. Suffering from jet lag occasionally when traveling is fine. But getting jet-lagged every day for years is seriously impairing all sorts of body functions (see reproduction above).
What is it about: Three groups of mice were fed a high-fat diet, each group getting exactly the same amount of food each day (and eating it all up each day). One group had free access to food at all times (and ate all the time). The second group was given food in a limited time regimen: a large breakfast and a small dinner. The third group was given all the food to gobble up in one large brekfast. The group that got only a large breakfast got obese, had other metabolic problems and had a disrupted expression of circadian genes.
What is new: Another interesting paper showing that timing of meals determines how the food is processed by the body.
Take-home message: Eating one big meal per day is bad for your health – spread it out a little.
Some more thoughts: The paper is interesting as the data suggest something different from most of the other papers in this line of research (see the next two papers below).
What is it about: Groups of mice were fed either normal or high-fat diet either with continuous free access to food or with feeding time limited to 8 hours during the night (remember that mice are nocturnal – this is their active period, i.e., their “day”). The results appear to be opposite from the paper above (by Fuse at al.) – it is the mice with unlimited feeding that got obese and developed metabolic problems, as well as reduced amplitude of the circadian gene expression.
What is new: Hmmm, which one of the two papers is “more right” than the other? The devil is in the details, so we’ll have to look there.
There are two obvious differences between the two papers. The Hatori paper gave full volume of the normal daily intake of food, while the Fuse paper gave mice only 80% of the normal food quantities per day – which is calory restriction in itself. This may explain why the free-feeding mice in Hatori paper got obese and developed problems, while the mice in the Fuse paper did not.
Second, there is a difference in timing of meals in time-restricted groups. There is “time-restricted feeding” and then there is “time-restricted feeding”! The Hatori paper restricted feeding to an 8-hour period starting one hour after lights-off and ending three hours before lights-on. The Fuse group gave breakfast at the moment of lights-off (the paper does not say for how long – presumably with reduced diet the hungry mice just ate it all very fast) and a smaller “dinner” at the moment of lights-on. These are very different timing schedules!
In many ways, the two-meal schedule of the Fuse paper is similar to the time-restricted schedule of the Hatori paper. Note that these two schedules did the best in regard to obesity and metabolism. Both the free-feeding (especially with the full diet in the Hatori paper) and extremely restricted feeding (brief but huge breakfast in the Fuse paper) resulted in bad metabolic effects. One can perhaps conclude that extremes are bad – one huge meal is bad as is continuous grazing, but that the spread of feeding over two or more smaller meals does better.
Take-home message: The perennial “more research is needed”….until then it is wise to eat your meals at normal times, more than once per day, no grazing in-between, and no midnight snacks…
Effect of feeding regimen on body weight and metabolism
Some more thoughts: Hatori paper is….overwhelming! There is so much work done. As I was reading it all, my thought was that ten pages in the middle of the paper could be completely cut out of the paper and the result would still remain exactly the same – just weigh the mice! All sorts of things were measured in a variety of ways, from gene expression patterns, to standard metabolic tests to histology. All that work strengthens the notion that obesity and metabolic problems are correlated, so the work is definitely not for nothing, and is very impressive. It certainly adds a lot of information to the notion that circadian clock is not just a timer, but intimately involved in regulation of metabolism.
Article: Till Roenneberg, Karla V. Allebrandt, Martha Merrow, Céline Vetter, Social Jetlag and Obesity. Current Biology, Volume 22, Issue 10, 939-943, 10 May 2012. doi: 10.1016/j.cub.2012.03.038
What is it about: A huge number of Europeans from various ages, latitudes and longitudes were assessed for a variety of circadian, sleep and health parameters. It turns out that most suffer from “social jet-lag” – an internal desynchronization between various body clocks as a result of continuous mismatch between the natural body rhythms and societally and culturally imposed wake-up, school, work and bed-time schedules. During the school/work week, people are massively sleep deprived. They then make up for it, “paying off the sleep debt”, over the weekends. The difference between the amount of sleep one gets on work/school nights and the amount of sleep one gets during the weekend is especially stunning in adolescents, whose internal clocks are naturally phase-delayed and thus most dramatically out of sync of what the society is forcing them to do:
Average sleep time by age and gender (top) and discrepancy between workday and weekend sleep (bottom)
One of the most remarkable results is that people with the largest workday/weekend discrepancy, the most socially jet-lagged individuals, are also most prone to smoking, drinking, obesity and other health problems. Naturally thin people (B) did not get obese if they were more sleep deprived, but those somewhat prone to obesity became obese if they were also sleep deprived due to social jet-lag:
Effect of social jetlag on obesity in obesity-prone people (top) and thin people (bottom)
What is new: Bits and pieces of this were known for a while. But nobody has ever done such a tremendous study on such a large number of people, controlling for so many factors and measuring so many parameters and so many outcomes. This is definitely a tour-de-force paper of the year in this field and is appropriately matched with a brand new book by the lead author – Internal Time: Chronotypes, Social Jet Lag, and Why You’re So Tired – which I am currently reading.
Take-home message: Socially imposed school and work schedules are messing with our health. Political will is needed to change the mindset, change the culture, and change the way we use time in the society.
Some more thoughts: This paper goes together well with the several papers described above – living a life outside of synchrony with the light-dark cycle of the natural environment (and no, artificial indoor light cannot match it) has serious health consequences, leading to metabolic, physiological, reproductive and psychological problems that negatively affect billions of people on Earth, and cost the society billions of dollars of lost productivity, unnecessary medical care, and loss of educational potential in teenage students. Watch the video:
Note: Again, and infuriatingly so, most of the interesting stuff is in the Supplemental Materials.
Genes are, for the most part, invisible to natural (and sexual) selection.
What evolution can work on are phenotypes – composites of anatomical, physiological and behavioral traits as they change during the development and lifetime of an organism. Genes are selected for, indirectly, inasmuch as they contribute to the phenotype. While in different organisms and in different cases selection may act on a number of different levels – genes, embryos, cells, organs, organisms, groups, species – usually the most important unit of selection is the individual organism.
How a gene contributes to the phenotype is affected by many factors – multiples ways of splicing it, multiple ways of post-translational modification, which other genes are present, where and when is it expressed during development, interactions between cells, tissues and organs, and interactions between the organism and its environment. As genes, chromosomes and genomes sometimes get duplicated, this provides more opportunities for traits, previously resulting from higher-level interactions, to get incorporated into the genetic instructions via the process of genetic assimilation.
The basic unit of life is the cell. A single-celled organism has to have all of its internal processes coordinated in order to display adaptive responses to the environment in order to survive and reproduce. In multi-celled organisms, each cell type has to behave properly, communicate properly with the other cells, and coordinate its activities with all the other cells in the body for the organism to display adaptive responses to the environment in order to survive and reproduce.
Molecules that do all, or almost all of the work are proteins. They build structures, they catalyze reactions, break down food, store and use energy, control communication between cells, regulate the expression of the genes, and more.
But proteins are hard to study! Nucleic acids are much easier – they are stable, inert, the 3D conformation does not matter, and laboratory techniques have been developed to discover, sequence and study snippets of DNA and RNA in ways that today can be done by middle-schoolers or in DIY science projects. When you have the hammer, everything is a nail. When you have genetic tools, your graduate students are instructed to use them. And then sometimes they forget why they are doing this in the first place…
We study nucleic acids because they are markers, or proxies, for proteins. We locate genes and hope that the processes of transcription, splicing and translation do not confound too much what the resulting proteins are and what they do. This means that study of genes – their sequences and patterns of expression – is a reasonable first step in studying a biological phenomenon as it provides us with tools and information needed to study proteins, cells and higher-order phenomena that are evolutionarily relevant.
Of the Big Four – anatomy, biochemistry, physiology, behavior – it is behavioral traits that are the furthest removed from the underlying genes. It is really difficult to find genes directly involved in behavior. Big screens for genes for behaviors usually come up with genes for kinases, neurotransmitter receptors, neuronal development factors and other generalized components of the nervous system.
Circadian clock is an exception. While one may argue that the clock is not actually a behavior but a physiological mechanism that regulates many other behaviors, it is still the closest to a behavioral trait we ever got in discovering underlying genetics. Most people in the field agree that all major genes involved in clock function have been discovered (mostly during the 1990s) and that it is not productive to search for more.
Sure, the Abstract book of last week’s SRBR meeting still contains some posters and blitz-sessions by students with a detailed genetics work (well, the students need to learn the techniques, right?), but most of the Big Honchos of the field have moved on – to properties of the entire cells, neural networks, properties of multi-clock systems, and interactions with the environment. In a sense, after a detour of the 1990s when all the focus and energy was placed into gene discovery (“opening the black box”), the field of chronobiology is going back to its roots – a historically incredibly comparative and integrative subdiscipline of biology.
For a long time we have thought of circadian clocks as simply timers – something that determines when other downstream functions happen. But evidence over the last couple of decades has accumulated that clocks are much more intimately involved in some of those functions, beyond just timing.
Ten years ago, when I was exiting the field, the interaction between clocks and metabolism was just starting to be explored. We learned that fruitfly clock-gene timeless is involved in cocaine addiction. We learned that mutations in clock genes that change circadian period also change other aspects of timing, from frequencies of fruitfly courtship songs, to developmental timing in nematodes, to photoperiodic responses, to reproductive cycles.
Today, involvement of the circadian clock in many aspects of metabolism is probably the most exciting and most heavily studied area in the field. And this is shown by all the papers I highlighted today. The focus away from identification of genes and moving on to proteins, cells, neural networks, multi-oscillatory systems, and interactions with the environment are making the field as exciting as ever, and in vanguard of much of the rest of biology which is still overly focused on DNA. And the findings have obvious and stark implications not just for our better understanding of Life, but also for understanding of adaptation of organisms to the changing climate, and for understanding the consequences on human health.
Over the years, Better Posters blog has become the “Go To” place to send students when they start preparing posters for their first scientific meetings. Updated weekly, on Thursdays, this blog by Dr. Zen Faulkes (who also blogs at his other two awesome blogs NeuroDojo and Marmorkrebs, as well as on the #SciFund blog) provides ideas, suggestions, underlying theory, and thorough, fair critiques of poster design for scientific conferences. It is a link I (and I am sure many others) send whenever asked what is the best resource for preparing a good poster. Zen Faulkes also has a broader category of posts about presentations in general, both oral and poster, under the Zen of Presentations tag on his other blog.
Anyone who has studied psychology or neuroscience will be familiar with the incredible case of Phineas Gage, the railroad worker who had a metre-long iron rod propelled straight through his head at high speed in an explosion. Gage famously survived this horrific accident, but underwent dramatic personality changes afterwards. In recent years researchers reconstructed his skull and the passage of the rod through it, to try to understand how these changes were related to his brain damage. Now, neuroscientists from the University of California, Los Angeles have produced Gage’s connectome – a detailed wiring diagram of his brain, showing how its long-range connections were altered by the injury.
Positive results in psychology can behave like rumours: easy to release but hard to dispel. They dominate most journals, which strive to present new, exciting research. Meanwhile, attempts to replicate those studies, especially when the findings are negative, go unpublished, languishing in personal file drawers or circulating in conversations around the water cooler. “There are some experiments that everyone knows don’t replicate, but this knowledge doesn’t get into the literature,” says Wagenmakers. The publication barrier can be chilling, he adds. “I’ve seen students spending their entire PhD period trying to replicate a phenomenon, failing, and quitting academia because they had nothing to show for their time.” These problems occur throughout the sciences, but psychology has a number of deeply entrenched cultural norms that exacerbate them. It has become common practice, for example, to tweak experimental designs in ways that practically guarantee positive results. And once positive results are published, few researchers replicate the experiment exactly, instead carrying out ‘conceptual replications’ that test similar hypotheses using different methods. This practice, say critics, builds a house of cards on potentially shaky foundations…
In 1964, the launch schedule for the Gemini program was set and it was tight. Missions with new objectives would launch every eight to ten weeks taking NASA a step closer to the Moon each time. But hardware setbacks and some surprising feats by Soviet cosmonauts took a toll on the schedule. In the first half of 1965, NASA developed a plan that would see Gemini match and begin to overtake the Soviet Union in space. It was done largely in secret and known internally as Plan X….
…The project of exhaustively collecting and describing the basic kinds of large animal, and analyzing and displaying these animals’ bodily parts and systems, is a project that gained momentum in the late Renaissance and that was largely completed by the end of the 19th century. Like, say, realist painting in the Western tradition, it is a project that has a bounded history (indeed the two histories fairly closely overlap one another). This means that an alpaca intestine displayed in formaldehyde is a sample of a part of a South American camelid; but it is also an artefact of a modern European knowledge project. In this respect a proper natural history museum, that is to say an unreconstructed adult natural history museum, is really two museums at once: it is a museum of nature, but also a museum of the history of a very singular attempt to know nature quite literally inside-out….
….To devise a good layout requires some understanding of what museum visitors do, and there’s surprisingly little literature on this topic. Most of the studies of museum-goers that I’ve seen rely on questionnaires. They ask people what they did, what they learned, and what they liked and didn’t like. No doubt there are virtues to this technique, but it assumes that people are aware of what they’re doing. It doesn’t take into account how much looking depends on parts of the brain that are largely instinctive and intuitive and often not easily accessible to our rational consciousness. Was there another mode of investigation and description that would illuminate what was actually taking place?…
You’ve probably heard of the “Pacific garbage patch,” also called the “trash vortex.” It’s a region of the North Pacific ocean where the northern jet stream and the southern trade winds, moving opposite directions, create a vast, gently circling region of water called the North Pacific Gyre — and at its center, there are tons of plastic garbage. You may even have seen this picture of the garbage patch, above — right? Wrong….
I love analogies and use them often to get people to think about scientific concepts in new ways. I’ll share some of my favourite ones on the blog but today, I want to talk about Analogies Gone Bad….There is a lovely analogy to help people understand DNA code: DNA can be seen as a language…
You might notice the sting of the injection. Within seconds you’d realize you’re having trouble moving your eyes and fingers, followed by your arms and legs. If you were standing, you’d collapse. In a heap on the floor, you’d realize nearly every muscle in your body was paralyzed. Being fully conscious, your sense of panic would be rising as rapidly as the paralysis was spreading. Swallowing and breathing has become more and more difficult. Slipping into unconsciousness, your last conscious thought may well be “I am going to die.”…
The American Psychiatric Association have just published the latest update of the draft DSM-5 psychiatric diagnosis manual, which is due to be completed in 2013. The changes have provoked much comment, criticism, and heated debate, and many have used the opportunity to attack psychiatric diagnosis and the perceived failure to find “biological tests” to replace descriptions of mental phenomena. But to understand the strengths and weaknesses of psychiatric diagnosis, it’s important to know where the challenges lie….
“Plants smell,” says botanist David Chamovitz. Yes, they give off odors, but that’s not what Chamovitz means. He means plants can smell other plants. “Plants know when their fruit is ripe, when their [plant] neighbor has been cut by a gardener’s shears, or when their neighbor is being eaten by a ravenous bug; they smell it,” he writes in his new book, What a Plant Knows. They don’t have noses or a nervous system, but they still have an olfactory sense, and they can differentiate. He says there’s a vine that can smell the difference between a tomato and a stalk of wheat. It will choose one over the other, based on…smell! In a moment I’ll show you how….
Any fair-sized city in the United States is lousy with pigeons, hoovering up bread crumbs from public squares and head-bobbing so much they look like little Jay Zs groovin’ to some fresh beats. The favorite rumpus room of the pigeon, New York City, is thought to contain anywhere between 1 and 7 million of the flapping rats of the sky. So where are all the dead ones?
Uncertainty overdone by Bryan Walker: “As a concerned human being I don’t want scientists to soft-pedal on that evidence.”
A Sensitive Subject, on quantifying uncertainties in modeling climate change and its impacts, by Tamsin Edwards:
Could Angry Birds lead to mass murder? by Martin Robbins: “Attempts to link last year’s Norway shootings to Call of Duty are spectacularly misguided. Moral panic about violent video games is based on prejudice, ignorance and the selective use of flawed research.”
This April 09, 2006 post places another paper from my old lab (Reference #17) within a broader context of physiology, behavior, ecology and evolution. The paper was a result of a “communal” experiment in the lab, i.e., it was not included in anyone’s Thesis. My advisor designed it and started the experiment with the first couple of birds. When I joined the lab, I did the experiment in an additional number of animals. When Chris Steele joined the lab, he took over the project and did the rest of the lab work, including bringing in the idea for an additional experiment that was included, and some of the analysis. We all talked about it in our lab meetings for a long time. In the end, the boss did most of the analysis and all of the writing, so the order of authors faithfully reflects the relative contributions to the work.
What is not mentioned in the post below is an additional observation – that return of the food after the fasting period induced a phase-shift of the circadian system, so we also generated a Phase-Response Curve, suggesting that food-entrainable pacemaker in quail is, unlike in mammals, not separate from the light-entrainable system.
Finally, at the end of the post, I show some unpublished data – a rare event in science blogging.
If you know what Chossat’s Effect is, I guess you are a) a physiologist, b) expert in thermoregulation, and c) old. This is term that got expunged from the scientific lexicon a few decades ago, in an effort – correct me if I am wrong on this – spearheaded by the U.S. textbook companies, to replace scientific terminology named after the discoverers (and sometimes even Latin and Greek terms) with bland English neologisms.
But I love Schwann’s Cells, Fallopian Tubes (or Mullerian Ducts), Purkinje Fibers, Brocca’s Area and the amazing Bundle of His! Those terms are memorable, make it easy to sneak in some historical context into teaching science, and have an emotional effect of bringing forth images of ancient scientists working under candlelight, sacrificing their eyesight and health, their social standing and sometimes even their lives, in the feverish hunger for knowledge.
So, what is Chossat’s Effect? It comes from a 19th century French scientist who was studying the physiology of starvation . The ‘modern’ term for this effect is “fasting-induced nocturnal hypothermia” (doesn’t that sound like something that would prompt the students in the classroom to immediatelly stop paying attention to the teacher and instead pick-up their cell-phones and start text-messaging their friends?).
Actually, this is a very interesting area of research that is very tightly connected to circadian biology. This post is likely to be long, so feel free to skim and just focus on the first part if you are into birds, second part if you are interested in mammals, and the last part if you are into humans.
All warm-blooded animals (and yes, that includes at least some reptiles, not to mention a few heat-producing plants like stink-cabbage) exhibit a daily rhythm of body temperature. If an animal is active during the day (diurnal) and sleeps during the night, reducing the metabolic rate during the night is a good way to save energy.
Some of the smallest birds, like swifts and hummingbirds, need to feed continuously in order to stay alive. At night, when they are not able to forage (flowers are closed, it’s hard to see, and owls are hunting at the time), they drop their metabolic rate, and thus body temperature, quite dramatically. The body temperature gets down as low as the environmental temperature, sometimes daringly close to the freezing point. The total drop can be as large as 40 degrees Celsius in some instances! This is called daily torpor (yup, click on that link – it is an excellent blog post) and the metabolic rate drops as much as 95% [2, 3]. This is like full-scale winter hibernation EVERY DAY!
Chossat’s effect does not refer to daily torpor, though. It describes a drop in temperature during the night that is larger than the usual circadian fluctuation, in animals undergoing fasting, e.g., during spells of very bad weather (e.g., hurricanes).
Normal amplitude (daily maximum minus nightly minimum) of body temperature in birds with normal access to food ranges between about 1 and 2 degrees Celsius. For instance, a daily maximum may be 41 degrees and the nightly minimum may be 39 degrees (yes, the birds are much warmer than mammals, which makes them inhospitable to microbes that cause many mammalian diseases), which calculates to 2 degrees of amplitude.
During fasting (or food deprivation in the laboratory), the nightly minima drop down to lower levels than in fed birds. The minimum gets lower and lower with each additional night. Importantly, the daily maxima do not change at all. It is thought that it is advantageous for birds to retain their normal metabolic rates during the day so they can immediately resume foraging once the bad weather subsides. Also, if the bad weather persists for too long, the birds need the daytime metabolic rates in order to fly away .
According to John Wingfield’s “Emergency Life-History Stage” hypothesis , an individual’s perception of inclement weather directly affect the levels of stress hormones (e.g., corticosterone). An individual who does not perceive the bad weather to be “too bad”, will reduce daytime activity and reduce night-time temperature in order to save energy – this individual has made a decision to sit it out.
On the other hand, an individual who perceives bad weather to be “really bad” (or if it lasts too long) will have higher levels of stress hormones and will attempt to fly away during the day. This is not the same mechanism as the seasonal migration, which is usually a nocturnal flight, i.e., they do not experience Zugunruhe, just stress. Stressed birds do not attempt to escape at night, at which time they have allowed their body temperature to drop by several degrees.
Nocturnal hypothermia has been studied in a large number of species of birds (see, for examples, references # 6-12), but most of the work was performed on pigeons [13-15] and quail . Not all avian species exhibit this response. Laurilla at al.  write:
“On the other hand, many large birds that are adapted to long fasting periods as a part of their life histories, e.g. penguins and geese (Cherel et al., 1988; Castellini andRea, 1992), owls (Hohtola et al., 1994) and some raptors (McKechnie andLovegrove, 1999) do not show marked hypothermia during fasting. Some species enter hypothermia upon food restriction only when isolated from conspecifics in a laboratory environment, while in the field they remain normothermic by huddling. These observations have even led some authors to question the usefulness of the concept of hypothermia (Lovegrove and Smith, 2003).”
Here is a graphic example of a fasting-induced nocturnal hypothermia in quail (from). The period between the two triangles is the time (3 days) during which the birds had water but no food. Before and after, birds were fed ad libitum. Below is a graph that shows the difference between the temperature minima during the first, second and third day (top) and night (bottom) of food deprivation in comparison to the last three days and nights of normal feeding prior to the fasting treatment: Much of the more recent research is looking at other environmental cues that can modify the Chossat’s effect, as well as the involvement of the circadian clock in this time-specific form of thermoreguluation.
For instance, some of the ambient cues that affect the response include ambient temperature [16, 20], ambient light , photoperiod [18, 19], single vs. repeated fasting [18, 19], caloric food restriction vs. complete food deprivation , social situation, e.g., opportunity for huddling  and presence of stationary vs. flying predators [19, 20]. Here is an example of an effect of ambient temperature on nocturnal hypothermia in fasted pigeons (from ). Lower the ambient temperature, deepeer the Chossat’s effect:
Here is the effect of the presence of a predator (from ). In the presence of a perched hawk (P), nocturnal hypothermia reached normally low levels. In the presence of the flying hawk (F), temperature did not drop as much. Presumably, the pigeons kept the metabolic rate high enough to be able to fly fast if needed:
As stated above, hypothermia occurs only during the night while the temperature during the days remains normal. However, all the studies are performed either in natural conditions of day and night or in light-dark cycles in the laboratory. In constant darkness, the circadian rhythm of temperature persists and hypothermia is apparent. Moreover, the temperature drops both at the minima during the ‘subjective night’ and at the maxima during the ‘subjective day’ (from ):
This suggests that light has a direct (or “masking“) effect on body temperature during the light-phase of the cycle. But is this effect acting directly on the thermoregulatory centers in the hypothalamus or is it mediated by the circadian clock that drives the rhythm of body temperature? In Japanese quail, the circadian pacemakers are located in the eyes. When the eyes are removed , both the daily maxima in the light-phase and the nightly minima during the dark phase drop, suggesting that the effect is mediated via the circadian clock, as the light perceived by the photoreceptors in the pineal gland and in the deep brain is incapable of keeping the daily maxima from dropping: Mammals
Some small mammals, such as smallest rodents and shrews, exhibit a full-blown daily torpor either normally  or in response to fasting . Here is an example of a daily torpor of a mouse-opposum:
In nocturnal animals, which many mammals are, body temperature is high at night when the animals are active and it drops during the day when the animals are sleeping. In rats, fasting induces diurnal hypothermia, i.e., drop of the daily minimum during the day (black circles, compared to pre- and post- treatment values in white symbols) while the nightly maxima remain unaffected : Chronic caloric food restriction leads to the drop in both the daily minima and nightly maxima of temperature . All the studies until recently have studied responses in relatively small animals (both birds and mammals) with high metabolic rates and high energy needs.
But do larger animals, like humans, also exhibit Chossat’s effect? After all, the first documented case, that by Chossat himself, was in a dog. This was repeated recently . But even dogs are pretty small compared to humans.
Recently, researchers have addressed this question in a number of species of large mammals, including sheep, goats, horses and yaks [26-29]. Some additional environmental cues were also studied, including the effects of shearing on the circadian temperature rhythm in sheep . Here is a record from a goat:
Notice that, unlike in birds, both the maxima and minima gradually go down.
But, as far as I could find by digging through the literature, nobody has ever performed a similar study in humans. I am assuming that it has been noticed if body temperature drops in fasted humans, but I am not aware of a study systematically addressing this question.
More than a decade ago I was teaching one of many sections of an Animal Anatomy and Physiology Course. This course requires students to perform a research project. One group of students studied the effects of fasting on body temperature and blood pressure in humans.
They found 8 subjects, all healthy, athletic, non-drinking, non-smoking students ages 19-23. They were instructed to eat normally during the Day1 of the experiment. They subsequently spent 36 hours in a house drinking only water and eating nothing. Every four hours, temperature and pressure were measured. By using kids’ digital ear thermometers and manual sphigmomanometers they managed, for the most part, not to awaken the subjects during the night. Here are examples of body temperature of three of the subjects – Night1, followed by Day2 and Night 2:
Here are the pooled data for all eight subjects, starting with Day2 and followed by Night1 and Night2 plotted on top of each other for comparison:
Obviously, body temperature of Night2, after a day of fasting, was lower than that of Night1, after the day of normal feeding. I do not have their raw data any more, but if I remember correctly, the data for blood pressure looked very similar. I heard they had a huge breakfast, courtesy of the young researchers, at the end of the experiment.
So, Chossat’s Effect appears to be operating in humans as well. Now, this is cool in itself, and I sure hope that someone with access to good clinical lab repeats this study, but there is something else about these data that really excites me. This finding can be used as a tool for studying something entirely different!
One of the first demonstrations that humans have daily rhythms involved the time-of-day dependence of time perception. In other words, our subjective “feel” of the speed of passage of time changes systematically with the time of day. At the same time, it has been known for a couple of centuries now that the subjective time perception is also altered during fever. And we know that circadian clock governs daily rhtyhms of body temperature.
So, what affects the time perception: time of day or body temperature? If the time passes faster in the evening than at dawn, is it because of the circadian clock acting on the time-perception brain-centers directly, or because we are warmer at the time (which is also driven by the circadian clock)?
This question has haunted circadian researchers for decades and they have devised ever more elaborate experiments to tease the two hypotheses apart, with no avail – we still do not know. But, if by depriving the subjects of food, we can dissociate clock-time from temperature, perhaps we can address this question after all. If the subjective perception of 1 minute (do not use 1 second or 1 hour – those are durations unsuited for this experiment) is similar between the night after a fed day and the night after the fasting day, then the perception is directly driven by the circadian clock.
If, on the other hand, perception of a minute changes systematically between the two nights, then we conclude that it is body temperature that affects subjective time perception. Please, someone do this! And if you do, or even if you just want to replicate the Chossat’s Effect in humans, I would appreciate it if you would properly cite this post:
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 Mirja Laurila, Esa Hohtola, The effect of ambient temperature and simulated predation risk on fasting-induced nocturnal hypothermia of pigeons in outdoor conditions, Journal of Thermal Biology 30 (2005) 392-399
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This is not really a new post. But it is not exactly a re-publishing of an old post either. It is a lightly edited mashup or compilation of excerpts from several old posts – I hope it all makes sense this way, all in one place. The sources of material are these old posts:
Nothing pains me more than when I see educators (in comments) revealing such biases in regards to their student in the adolescent years. Why do teachers think that their charges are lazy, irresponsible bums, and persist in such belief even when confronted with clear scientific data demonstrating that sleep phase in adolescents is markedly delayed in comparison to younger and older people?
In short, presumably under the influence of the sudden surge of sex steroid hormones (and my own research gently touched on this), the circadian clock phase-advances in teen years. It persists in this state until one is almost 30 years old. After that, it settles into its adult pattern. Of course, we are talking about human populations, not individuals – you can surely give me an anecdote about someone who does not follow this pattern. That’s fine. Of course there are exceptions, as there is vast genetic (and thus phenotypic) variation in human populations. This does not in any way diminish the findings of population studies.
Everyone, from little children, through teens and young adults to elderly, belongs to one of the ‘chronotypes’. You can be a more or less extreme lark (phase-advanced, tend to wake up and fall asleep early), a more or less extreme owl (phase-delayed, tend to wake up and fall asleep late). You can be something in between – some kind of “median” (I don’t want to call this normal, because the whole spectrum is normal) chronotype.
Along a different continuum, one can be very rigid (usually the extreme larks find it really difficult to adjust to work schedules that do not fit their clocks), or quite flexible (people who find it easy to work night-shifts or rotating shifts and tend to remain in such jobs long after their colleagues with less flexible clocks have quit).
No matter where you are on these continua, once you hit puberty your clock will phase-delay. If you were an owl to begin with, you will become a more extreme owl for about a dozen years. If you are an extreme lark, you’ll be a less extreme lark. In the late 20s, your clock will gradually go back to your baseline chronotype and retain it for the rest of your life.
The important thing to remember is that chronotypes are not social constructs (although work-hours and school-hours are). No amount of bribing or threatening can make an adolescent fall asleep early. Don’t blame video games or TV. Even if you take all of these away (and you should that late at night, and replace them with books) and switch off the lights, the poor teen will toss and turn and not fall asleep until midnight or later, thus getting only about 4-6 hours of sleep until it is time to get up and go to school again.
More and more school districts around the country, especially in more enlightened and progressive areas, are heeding the science and making a rational decision to follow the science and adjust the school-start times accordingly. Instead of forcing teenagers to wake up at their biological midnight (circa 6am) to go to school, where invariably they sleep through the first two morning classes, more and more schools are adopting the reverse busing schedule: elementary schools first (around 7:50am), middle schools next (around 8:20am) and high schools last (around 8:50am). I hope all schools around the country eventually adopt this schedule and quit torturing the teens and then blaming the teens for sleeping in class and making bad grades.
No matter how much you may wish to think that everything in human behavior originates in culture, biology will trump you every now and then, and then you should better pay attention, especially if the life, health, happiness and educational quality of other people depends on your decisions.
Recently, Lance Mannion wrote an interesting post on the topic, which reminded me also of an older post by Ezra Klein in which the commenters voiced all the usual arguments heard in this debate.
There are a couple of more details that I have not touched upon in the previous posts.
First, lack of sleep can lead to obesity and even diabetes, as the circadian clock is tightly connected to the ghrelin/leptin system of hormonal control of hunger, feeding and fat-deposition.
Second, lack of sleep discourages exercise. Put these two pieces of data together, and you get a national epidemic of obesity, not just a bunch of sleep-deprived children.
Third, lack of sleep has a well-documented effect on mood. No, teenagers are not naturally that moody – at least not all of them. They are just barely “functional” (instead of “optimal”) and walk through life like zombies because they are operating on 4-8 hours of sleep instead of 9 hours (optimal for teens, it goes down to about 8 for adults). Of course they are moody.
Fourth, chronic sleep deprivation can have long-term consequences, ranging from psychiatric diseases to cancer. Remember that teens in high-school (and college students are faring worse!) are constantly jet-lagged!
There is even a hypothesis floating around that sleep-delay in adolescence may affect the onset of picking up smoking.
Fifth – and I did not think of this although it is obvious – teenagers above a certain age, still in high school, are allowed to drive. If they are driving themselves to school at 6 or 7am, when their circadian clocks think is it 3 or 4am, it is as if they are driving drunk. There is actually a scale devised by one of the sleep researchers that tells which time of the night corresponds to what number of bottles of beer. Driving at 4am (or driving a ship, like Exxon Valdez, or operating a power-plant, like one in Chernobyl) is the equivalent of driving drunk – way over the legal limits. Teenagers driving at 7am are equally “drunk”.
One of the reasons for the resistance to healthy initiatives to change school-start schedules stems from the fact that the world is organized by adults and adults want to have the world run according to schedules that fit their moods and are unwilling to change it – they may not know that teens feel differently, or they defend their preferences nonetheless.
A large proportion of adults in this country still subscribe to barbaric notions that sleep is a shameful activity, a sign of laziness, and that teens need to be tortured in order to “steel” them to grow into “real men”. This has roots all the way back to the Puritan so-called “work-ethic” which is really a “no fun for anyone” punitive ethic long ago shown to be physically and emotionally debilitating.
When I was a kid, back in old now-non-existent Yugoslavia, most schools in big urban areas worked in two shifts. All the kids started school at 8am and ended at 1:15pm for one week, then started at 2pm and ended at 7:15pm the next week, and so on…
If a school had, let’s say, twelve classes of the seventh grade, six of those would be in the A-shift and the other six in the B-shift. Each shift had its own complete set of teachers, assistants, nurses…everything except the one shared Principal and the school psychologist.
The time between 1:15pm and 2pm was for supplementary classes (either for those who needed extra help, or for those preparing for Math Olympics and such) and clubs. That was also time for kids from two shifts to meet and get to know each other (it is amazing how many kids from opposite shifts started dating each other after the year-end Big Trip to the Coast). There was no such thing as the American hype for high-school competitive sports, which I still find strange and curious after 15 [now 20] years in this country.
Thus, you get to sleep in for a week (but miss out on afternoon activities), then have to get up relatively early for a week but have the afternoon free to gallivant around town. Nobody there understands what’s the American fuss over kids being home alone – of course they are home alone, cleaning the house, fixing meals, doing homework and BETTER be getting to school on time!
Teachers were pretty understanding about sleeping types. I do not recall ever having a big test, quiz or exam being given at the extremes of the day (around 8am or around 7pm). As an owl myself, I was much more likely to raise my hand, participate in discussions, or volunteer for oral examinations during the week when I was in school in the afternoon, and that was fine with most of my teachers.
Transportation was not an issue. Most kids lived close enough to their neighborhood school to walk. For those who lived a little farther away – hey, no problem, that’s Europe, so Belgrade has a huge and pretty efficient public transportation system. I do not remember ever seeing any of my friends ever being dropped off to school by a parent driving a car! Or being brought to or picked up from school by a parent beyond fourth grade at all – period. And the minimum driving age being 18, nobody drove themselves to school either.
In rural areas, there was no need for two shifts – something like 9am-2:15pm was good enough to accommodate all of the kids.
I do not think that this kind of system can be implemented in the USA. It relies on an efficient public transportation which, with exception of a few oldest East Coast cities, is practically non-existent. American cities have been built for cars.
But some things can be done.
First, swap the starting times so elementary kids go to school first, middle school next and high school last (e.g., around 8am, 8:30am and 9am respectively). Studies show that teens do not go to sleep later if their school starts later. Some cynics claim that is what teens will do. But they do not. Actually, they fall asleep at the same time, thus gaining an additional hour of sleep.
Teens are almost adults. The current generation of teens, perhaps because of a closer and tighter contact with their parents than any generation before, is the most serious, mature and responsible generation I have seen. Give them a benefit of the doubt. Just because you were into mischief and hated your parents when you were their age does not mean that today’s kids are the same.
Second, start the school day – for all kids every day – with PE (or some kind of exercise), preferably outdoors, as both exposure to daylight and the exercise have been shown to aid in phase-shifting the circadian clock.
Third, let them eat breakfast afterwards (sticking to a meal schedule also helps entrain the clock). Follow up with the electives which kids may be most interested in.
By the time they hit math, science and English classes around 11 or so, their bodies are finally fully awake and they can understand what the teacher is saying, and do the tests with a clear mind instead of in a sleepy haze.
Do not permit any caffeine to be sold in schools. Advise parents not to allow TV or any other electronics to be in kids’ bedrooms. Let them enjoy those activities in the living room. Bedroom is for sleeping, and sleeping alone. A book before bed is fine, but screens just keep them awake even longer.
Finally, rethink all those extra activities you are forcing the teens to do: sports, art, music, etc. In teen’s minds, the day does not start with the beginning of school in the morning. We may think that we are at work most of our day. Teens do not – they consider their day to begin at the time school-day is over. Their day begins in the afternoon. School is something they have to deal with before they can have their day. Realize this and give them time and space to do with their day what they want. Do not push them to do things that you think they’ll need to get into Harvard. Let them be – leave them alone. Then they’ll go to sleep at a normal time.
Concern for our kids’ physical and mental health HAS to trump all other concerns, including economic costs, cultural traditions and adult preferences. We have a problem and we need to do something, informed by science, to fix the problem. Blaming the messenger, proposing to do nothing, and, the worst, blaming the kids, is unacceptable.
All of this targets high-schoolers. However, there is barely any mention of college students who are, chronobiologically, in the same age-group as high-school students, i.e., their sleep cycles are phase-delayed compared to both little kids and to adults.
In a way, this may be because there is not much adults can do about college students. They are supposedly adults themselves and capable of taking care of themselves. Nobody forces (at least in theory) them to take 8am classes. Nobody forces them to spend nights partying either.
They are on their own, away from their parents’ direct supervision, so nobody can tell them to remove TVs and electronic games out of their bedrooms. The college administrators cannot deal with this because it is an invasion of students’ privacy.
Forward-looking school systems in reality-based communities around the country have, over the last several years, implemented a policy that is based on science – sending elementary school kids to school first in the morning, middle-schoolers next, and high-schoolers last. This is based on the effects of puberty on the performance of the human circadian clock.
For teenagers, 6am is practically midnight – their bodies have barely begun to sleep. Although there have been some irrational (or on-the-surface-economics-based) voices of opposition – based on outdated notions of laziness – they were not reasonable enough, especially not in comparison to the scientific and medical information at hand, for school boards to reject these changes.
I am very happy that my kids are going to school in such an enlightened environment, and I am also happy to note that every year more school systems adopt the reasonable starting schedules based on current scientific knowledge.
Yet, college students are, from what I heard, in much worse shape than high-schoolers. Both groups should sleep around 9 hours per day (adults over thirty are good with about 8 hours). High-schoolers get on average 6.9 hours. College students are down to about five! The continuous insomnia of college students even has its own name in chronobiology: Student Lag (like jet-lag without travelling to cool places). Is there anything we, as a society, can do to alleviate student lag? Should we?
One of the recurring themes of my blog is the disdain I have for people who equate sleep with laziness out of their Puritan core of understanding of the world, their “work ethic” which is a smokescreen for power-play, their vicious disrespect for everyone who is not like them, and the nasty feeling of superiority they have towards the teenagers just because they are older, bigger, stronger and more powerful than the kids. Not to forget the idiotic notions that kids need to be “hardened”, or that, just because they managed to survive some hardships when they were teens, all the future generations have to be sentenced to the same types of hardships, just to make it even. This is bullying behavior, and disregarding and/or twisting science in the search for personal triumphalism irks me to no end.
I hated getting up early, too. I still hate it, and I’m so far beyond growth hormones that I don’t even remember how they felt. But I do remember that in middle and high school, I dragged myself out of the house at 5 a.m. every day of the week to deliver papers before I caught the 6:45 a.m. bus to school. I never fell asleep in class. Neither did anybody else. And something caused me to grow 6 inches and add 35 pounds between sophomore and junior year. At the end of that kind of day, complete with cross-country, basketball or track, I had no trouble falling asleep at 10 p.m.
He said that he grew up in height and weight when he was in high school. Who knows how much more he would have grown if he was not so sleep deprived (if his self-congatulatory stories are to be believed and he did not slack off every chance he had). Perhaps he would not grow up to be so grouchy and mean-spirited if he had a more normal adolescence.
I don’t know where he got the idea that growth hormone is a cause of the phase-delay of circadian rhythms in adolescence. It could be, but it is unlikely – we just don’t know yet. But, if a hormone is a cause, than it is much more likely to be sex steroids. Perhaps his sleep-deprived and testosterone-deprived youth turned him into a sissy with male anxiety he channels into lashing at those weaker than him?
In previous centuries, adolescents in an agrarian society got up at 4:30 or 5a.m. with their parents to milk the cows or do any other of a long list of chores. Did growth hormones pass them by? Where were the “studies” that showed they really needed to go to bed after midnight and sleep until 10? And why weren’t their parents all being reported to the DSS? Oh, that’s right, there was no DSS. How did that generation survive?
He assumes that in times before electricity, teenagers used to wake up and fall asleep at the same time adults did. Well, they did not. Studies of sleep patterns in primitive tribes show that adolescents are the last ones to wake up (and nobody bashes them for it – it is the New Primitives with access to the media that do that) and the last ones to fall asleep – they serve as first-shift sentries during the night watch.
Even in this, the 21st century, kids who enter the military at 17 find that they can fall asleep easily at 9:30 or 10, because they know they’re going to be getting up at 4:30 or 5. Apparently the Army hasn’t read the study on circadian rhythms.
Actually, the military being the most worried by this problem is funding a lot of research on circadian rhythms and sleep and has been for decades. Because they know, first hand, how big a problem it is and that yelling sargeants do not alert soldiers make.
Kids, if you need more sleep, my study shows there’s a simple way to get it. Turn off – I mean “power down” – the cell phone, the iPod and the computer sometime before 11 p.m. Turn off the TV. Turn off the light. Lie down in bed and close your eyes.
…and sit in the dark for the next four hours, heh?
What especially drives me crazy is that so many teachers, people who work with adolescents every day, succumb to this indulgence in personal power over the children. It is easier to get into a self-righteous ‘high’ than to study the science and do something about the problem. It is easier to blame the kids than to admit personal impotence and try to do something about it by studying the issue.
My regular readers are probably aware that the topic of adolescent sleep and the issue of starting times of schools are some of my favourite subjects for a variety of reasons: I am a chronobiologist, I am an extreme “owl” (hence the name of this blog), I am a parent of developing extreme “owls”, I have a particular distaste for Puritanical equation of sleep with laziness which always raises its ugly head in discussions of adolescent sleep, and much of my own past research was somewhat related to this topic.
So, I was particularly pleased when Jessica of the excellent Bee Policy blog informed me of the recent publication of a book devoted entirely to this topic. Snooze…or Lose! by Helen Emsellem was published by National Academies and Jessica managed to get me an advanced reading copy to review.
Her daughter Elyssa wrote one of the chapters in the book and is promoting the book and the information relevant to teenagers at the place where teenagers are most likely to see it – on MySpace (you see – it’s not just music bands who caught onto this trick – serious information can be promoted at MySpace as well).
The main audience for this book are teenagers themselves and their parents – I think in this order although officially the order is reversed. Secondarily, the audience are teachers, administrators and officials in charge of school policy. Who this book is not targeted to are scientists and book reviewers because there are no end notes!
Anyway, considering that the main audience are teens, their parents and teachers (i.e., laypeople), the book is admirably clear and readable. The book starts out with presenting the problem – the chronic sleep deprivation of adolescents in modern society – and provides ample evidence that this is indeed a wide-spread problem. It continues with a simple primer on physiology of sleep and circadian rhythms, followed by a review of the current knowledge of the negative consequences of chronic sleep deprivation: from susceptibility to diseases, through psychological and behavioral problems, to problems of physical and mental performance.
A whole chapter – the one I found most interesting – is devoted to the role of sleep in various kinds of memory and the negative effects of sleep deprivation on learning – both declarative and episodic memory, as well as kinesthetic memory needed for athletic performance and safe driving. This is where I missed the end notes the most.
Throughout the book, Dr.Emsellem makes statements of fact about sleep that are obviously derived from research. I’d like to see the references to that research so I can evaluate for myself how strong each such statement is. Although my specialty is chronobiology (physiology, development, reproduction, behavior, ecology and evolution) of birds, and secondarily that of mammals, reptiles, invertebrates and microorganisms (I could never quite get excited about clocks in fish, fungi and plants, or molecular aspects of circadian rhythms, or medical aspects of human rhythms), I am quite familiar with the literature on sleep, including in humans.
Thus, I know that the statements in the book reflect scientific consensus but that the meaning of “consensus” is quite elastic. In some cases, it means “there is a mountain of evidence for this statement and no evidence against it, so it is highly unlikely that this will change any time soon”. In other cases it means “there are a few studies suggesting this, but they are not perfect and there are some studies with differing results, and this can stand for now but is likely to me modified or completely overturned by future research”.
Having end notes would help the expert reader see how weak or strong each one of these findings is, and would also be suggestive to lay readers that the statements in the book are supported by actual research and are not just the author’s invention as seen in so many self-help books. End notes and references add to the believability of the text even if one does not bother to check the papers out.
The book then turns to variety of factors, both biological and social, that conspire to deprive our teens of sleep, both from the perspective of a sleep researcher and from the perspective of teenagers. Little snippets of teenagers’ thoughts on the topic are included throughout the book and add an important perspective as well as make the book more fun to read. Otherwise, the “case studies”, the bane of so many psychology books, are kept to the minimum, discussed very briefly, and used wisely..
In the next section, Dr.Emsellem turns to solutions. First, she present several tests of sleep deprivation that readers can administer themselves in order to self-diagnose the problem. She then describes ten different strategies that parents and teens can work on together in order to solve the problem of sleep deprivation and all the concomittant negative effects (and Alyssa adds her own chapter on the teen perspective on how those can work). If that does not work, she describes additional methods that a sleep doctor may prescribe to help solve the problem. There is also a short chapter describing a couple of other sleep disorders, e.g., sleep apnea, that also contribute to sleep deprivation in affected individuals.
The last portion of the book addresses the social aspects of sleep deprivation and changes that parents and teens can make in their homes, as well as broader community, towards solving the problem. For adults, being a role model for the child is important and this requires paying attention to one’s own sleep hygiene.
The very last portion is really the raison d’etre of the book – how to make one’s community change the school starting times. The author presents a couple of examples of school districts in which such change was enacted, the strategies parents used to force such changes and the incredible positive results of such changes. The whole book is really designed to provide information to parents and teens who are working on changing their local attitudes toward school starting times.
The schools used to start about 9am for most of the century (and before). Then, due to the pressure from business and economic (read “busing”) woes of school districts, the school starting times started creeping earlier and earlier starting back in 1970s until they reach the horribly early times seen today in many places, requiring kids to get up as early as 5am in order to catch the school bus on time. As a result, high schoolers (and to some extent middle schoolers and college students) sleep through the first two periods in school, feel weak and groggy all day long, more easily succumb to diseases, have trouble learning and performing well in school and the athletic field, and are in too bad mood to be pleasant at home – this is not the natural state of things as much as the stereotype of the “grouchy teen” is prevalent in the society, it is mainly due to sleep deprivation and the biggest factor causing sleep deprivation are early school starting times.
In places in which enlightened and progressive school boards succumbed to the wishes of parents and students, i.e., in places in which parents and students used smart diplomatic tactics to engender such change, the positive results are astounding. The grades went up. The test scores went up. The students are happy. The parents are happy. The teachers are happy. The coaches are happy because their teams are winning all the state championships. There is a decrease in tardiness and absences. There is a decrease in sick days and even in numbers of diagnoses of ADD and depression in teens. There is a drop in teen crime. There is a drop in car accidents involving teens (by 15% in one place!). The whole county feels upbeat about it!
While the book makes me – a scientist – thirsty for end notes and references, it does remarkably well what it was designed to do – arm the parent and kids with knowledge needed to make a positive change in their communities – a change that is necessary in order to raise new generations to be healthy and successful, something we owe to our children.
We should do this no matter how much it costs, but the experiences from places in which the changes were made, contrary to doomsayers, is that there was no additional cost to this at all. The changes were implemented slowly and with everyone involved pitching in their opinion and their expertise until the best possible system was arrived at, adapted to the local community situation. No new buses were needed to be rented. No unexpected new costs appeared. And having a safe, happy community saved money elsewhere (e.g., accidents and crime rate decline). And it worked wonderfully everywhere.
So, get the book and let your child read it, you read it, give a copy to other people in your community: the teachers, the school principal, the pediatrician, the child psychologist, the school board members, the superintendent of education and the governor. This is something that is easy to do, there are no good reasons against it and the health and the future of our kids is at stake. It is something worth fighting for and this book is your first weapon.
It addresses some of the themes I am interested in.
First, the unfortunate fact is that sleep was initially defined by researchers of humans, i.e., medical researchers. Inevitably, the (electrophysiological) definition of sleep was thus saddled with unnecessary anthropocentric elements that for decades hampered the study of evolution of sleep.
I was present at the meeting (here in Biotechnology Center in RTP) several years ago when the bigwigs of the sleep research community were first exposed to some very new ideas via not one but two talks about sleep in fruitflies (by Marcia Belvin and Joan Hendricks). That was quite an earthshaking event as the definition of sleep was substantially changed right then and there. Interestingly, the new (behavioral) definition was received not with resistance but with enthusiasm. Everyone in the room understood the potential of the new way of thinking to break off the shackles that sleep research had to suffer in for so long.
Since then, the marriage of circadian and sleep research has resulted in sleep research taking off at a breathtaking speed. As a result, many old assumptions and dogmas had to be discarded. For many years sleep researchers shunned evolutionary explanations and focused on physiological and medical aspects of the phenomenon. However, progress in sleep medicine depends on a better understanding of what sleep is for – a decidedly evolutionary question.
Another theme is the old battle between adaptationism and the more sophisticated view of evolution that incorporates the phenomena of developmental and phylogenetic constraints, as well as the concept of exaptation. Just because a mechanism currently serves a particular function does not mean that this function is what the mechanism originally evolved for. In other words, current function is not necessarily the original function (bird wings were initially adaptations for thermoregulation and later got exapted for flight). Here is the adaptationist statement:
The theorists have long disagreed about one another’s ideas, but most agree on one thing: If nature makes people sleep away so much of their lives, the reason has to be something crucial. That seemed to be the only way to explain why sleep-deprived people crave sleep so badly that they doze off behind the wheel of a car going 60 mph, and why rats deprived of sleep die sooner than rats deprived of food.
The article then trots out a couple of currently favoured hypotheses about the adaptive function of sleep:
Yet a wealth of sleep research has regularly produced baffling paradoxes and conflicting lines of evidence about the uses, role and need for sleep. If sleep is primarily about providing mental rest, why do people’s brains remain so active during sleep, as research in recent decades has found?
If sleep is about providing the body with rest, why do couch potatoes need as much sleep as Olympic athletes? Moreover, animals such as horses, which perform far more physical labor than humans, need much less sleep than people do.
If sleep primarily hones cognitive functions, why do the intellectually lazy need as much sleep as Nobel Prize-winning physicists? Also, why do humans — who are a lot smarter than rats — sleep less than rodents?
Finally, while much conventional thinking suggests that Americans should be sleeping more, a very large 2002 study found that people who sleep eight hours or more a night are likely to die younger than those who sleep seven. (Don’t touch that alarm clock; the study did not find that deliberately sleeping less increases life span.)
Considering that a vast majority of sleep researchers are MDs, not neccessarily up to speed in evolutionary theory, such sentiments are not surprising. It takes an evolutionary biologist to move the ball forward:
Jerome Siegel, a psychiatrist at the University of California at Los Angeles who described these discordant findings in acomprehensive review of the available research, published in the journal Nature last week, said he began to question the notion that sleep performs some essential function after noting that species that sleep less than others do not sleep any deeper — as they would if they were making up for the shorter time. Animals that sleep fewer hours generally sleep less deeply, while animals that sleep longer usually sleep more deeply.
Siegel, a respected sleep researcher who is also affiliated with the Department of Veterans Affairs, said he came to the conclusion there was only one explanation that could explain the paradoxes: in a word, evolution.
Rather than being designed to perform some critical function, Siegel wrote in his paper, sleep may be the way various species, humans included, have adapted to their ecological niches. While many valuable functions probably take place during sleep, Siegel suggested that it is possible that those functions are not the reason for sleep.
“There is this huge variation in sleep across species, and it fits with this huge variation in the niches that animals occupy,” Siegel said in an interview.
“The analogy I make is between hibernation and sleep,” he said. “No one says, ‘What is hibernation for? It is a great mystery.’ . . . It’s obvious that animals hibernate because there is no food, and by shutting down the brain and body they save energy.”
Sleep, Siegel suggested, may play much the same role. As evidence, he cited research that has found systematic differences in the way carnivores, omnivores and herbivores sleep: Carnivores sleep longer; herbivores, shorter; and omnivores, including humans, are somewhere in the middle.
“If animals have to eat grass all day, they can’t sleep a lot, but if they eat meat and are successful at killing an antelope, why bother to stay awake?” he asked.
On the other hand, mammals at greater risk of being eaten — such as newborns — spend large amounts of time asleep, presumably safe in hiding places devised by their parents. Supporting the evolutionary explanation, Siegel’s own research has shown that when the luxury of safe hiding places is unavailable — in the ocean, for instance — baby dolphins and baby killer whales reverse the pattern found among terrestrial mammals. These marine mammals sleep little or never as newborns and gradually increase the amount they sleep as they mature.
Let me put it simply: sleep makes you sit still and be quiet at times when it is dangerous to move around and there is nothing else important to do. All the other functions were added later due to either timing (some things are better done at certain times of day that coincide with either sleep-time or wake-time and the two processes get linked) or particular brain states (i.e., some functions, for instance the consolidation of memory, are easier to perform at times when the brain is NOT receiving much input from the outside environment):
The theory does not so much contradict other theories about the role of sleep as much as place them in context: “What I am saying is that it is not that sleep has been adapted to allow some vital function to be fulfilled, but the core function of sleep is to adapt animals to their ecological niche,” Siegel said. “Given the animal is inactive for a certain period of the day, certain functions will migrate to that period because it is more efficient” to perform them at that time.
Interestingly, this hypothesis does not conflict with an old (and frankly quite unpopular) notion that mammals and birds did not evolve sleep as a new process (after all, insects sleep, we now know), but that they evolved wakefulness as a novel state of the mind.
Insects, fish, amphibians, reptiles etc., have periods of activity and periods of slumber. The period of slumber corresponds to mammalian/avian state of sleep. But, the active state in cold-blooded animals is more similar to sleep-walking than real wakefulness.
Did birds and mammals independently evolve wakefulness or was there a whole suit of (now extinct) reptilian and dinosaurian lineages who were also wide awake? Did evolution of wakefulness provide a substrate for the evolution of consciousness? Interesting speculations, but nothing close to an answer to date. At least, provocative hypotheses by Jerome Siegel and some others are prompting the sleep scientists to reconsider everything they hold dear and therein lies progress.
For the greatest portion of the history of biology, every organism was a “model organism”. One would pick a problem and then choose which organism would be most suited for answering those particular questions. Then, in the 1990s, everyone jumped onto the bandwagon of studying just a handful of organisms that could be genetically modified at the time: mouse, fruitfly, thale cress, zebrafish, African clawed frog, bread mold, brewer’s yeast, or E.coli. All the other organisms were all but abandoned, only studied by a small number of die-hard researchers and, increasingly, amateurs. Now that technology allows us to investigate (and to some extent manipulate) entire genomes of almost any species we’d like, researchers are going back and rediscovering the abandoned model organisms once again. One of these is Anolis, a large group of species of lizards, noted for their dewlaps, and known especially for their fast adaptive radiation on tropical islands.
And now there is a blog that covers everything about these lizards – Anole Annals. Posts are written both by veteran researchers and their students, from several laboratories, as well as other contributors. They cover both recent and historical papers on evolution, ecology, biogeography, behavior, physiology, biomechanics and genetics of this diverse group of reptiles. They also describe their own research, including anecdotes and adventures from field work, equipment they use in the lab, and successes in discovery. On top of that, they help people ID the species from pictures, pay attention to the appearance of anoles in art and in the popular culture and generally have a lot of fun doing all of this. A blog entirely devoted to just one group of animals sounds very ‘niche’, but what they did was build a blog that has something for everyone and is a great fun (as well as insightful and educational) read for everyone.
…Today we take for granted that all material objects in the universe are comprised of discrete “bits” of matter, which we call atoms; however, even up until the early 20th century there were still proponents of the continuum hypothesis, in which all matter is assumed to be infinitely divisible…
I’m sure many mothers can attest to the following: You have friends who also are mothers. I bet that for most of us, those friends represent a spectrum of attitudes about parenting, education, religion, Fifty Shades of Grey, recycling, diet, discipline, Oprah, and more. They also probably don’t all dress just like you, talk just like you, have the same level of education as you, same employment, same ambitions, same hair, or same toothpaste. And I bet that for many of us, in our interactions with our friends, we have found ourselves judging everything from why she insists on wearing those shoes to why she lets little Timmy eat Pop Tarts. Yet, despite all of this mental observation and, yes, judging, we still manage to get along, go out to dinner together, meet at one another’s homes, and gab our heads off during play dates. That’s not a war. That’s life….
The Earth’s earliest days were largely free of oxygen. Then, around 2.5 billion years ago, primitive bacteria started to flood the atmosphere with this vital gas. They produced it in the process of harnessing the sun’s energy to make their own nutrients, just as plants do today. The building oxygen levels reddened the planet, as black iron minerals oxidised into rusty hues. They also killed off most of the world’s microbes, which were unable to cope with this new destructive gas. And in the survivors of this planetary upheaval, life’s first clock began to tick and tock….
Earlier this week, the Tibetan Buddhist leader, the Dalai Lama, told British journalists that he’d been warned of an ingenious Chinese plot to assassinate him with poison. Very ingenious, according to the plot he laid out for the Sunday Telegraph. He’d learned, he said, of a plan to send out a squad of women, pretending to be followers, who would have poison spread through either their hair or headscarves. When he laid his hands on their heads for a blessing, a lethal dose could be absorbed through his skin…
….But sometimes tapeworms take a wrong turn. Instead of going into a pig, the eggs end up in a human. This can occur if someone shedding tapeworm eggs contaminates food that other people then eat. When the egg hatches, the confused larva does not develop into an adult in the human’s intestines. Instead, it acts as it would inside a pig. It burrows into the person’s bloodstream and gets swept through the body. Often those parasites end up in the brain, where they form cysts….
Next time the government wants new ideas about how to protect our nation’s security, it should consult an octopus. That’s the unusual proposition of marine biologist Rafe Sagarin, a pioneer in the infant field of “natural security,” where experts use models from nature to help them come up with emergency responses to everything from terrorist attacks to pandemics. Sagarin has just published a book about his work called Learning from the Octopus: How Secrets from Nature Can Help Us Fight Terrorist Attacks, Natural Disasters, and Disease. Any scientific theory that involves the superiority of cephalopods is automatically intriguing, so I called up Sagarin to talk about it.
Yesterday the DSN crew first saw the video above. What is this large floating sheet of goo? Is it alive? Was it once alive? The two leading contenders seems to be that it is A) an old whale placenta or B) a rare and enigmatic deep-sea jellyfish. And the answer is…. B)
….The problem is that most of the popular physics that the public enjoys constitutes perhaps 10% of the research that physicists worldwide are engaged in. Again, count the number of physics books in your local bookstore, and you will notice that about 90% of them cover quantum mechanics, cosmology, particle physics and “theories of everything”. You would be hard-pressed to find volumes on condensed matter physics, biophysics, the physics of “soft” matter like liquids and non-linear dynamics. And yes, these are bonafide fields of physics that have engaged physics’s best minds for decades and which are as exciting as any other field of science. Yet if you ask physics-friendly laymen what cutting-edge physics is about, the answers will typically span the Big Bang, Higgs boson, black holes, dark matter, string theory and even time-travel. There will be scant mention if any of say spectroscopy, optics, polymers, magnetic resonance, lasers or even superconductivity….
I wish I could take dinosaurs away from the media for a while. Someone certainly should. Lazy journalists and unscrupulous documentary creators have amply demonstrated that they just can’t play nice with Tyrannosaurus, Triceratops and kin…
What leads people to acts of violence and genocide? What triggers empathy and altruism? Duke evolutionary biologist Brian Hare and research scientist Vanessa Woods believe the answer may be found in the great ape known as the bonobo….
Most organisms that live on or near the surface of the Earth or its oceans have evolved a circadian clock – a daily timer of all biochemical, physiological and behavioral functions.
Daily cycle of light and darkness in the environment is a selective factor – having an internal clock is an adaptation that allows organisms to predict and prepare for instead of passively react to cyclical changes in the environment. The regularity of the light-dark cycle is usually a good predictor for other (perhaps not as precise) cycles of temperature, availability of food, or activity of predators.
It gets trickier for organisms that live in places where the light-dark cycle may be missing for big chunks of the year (the polar regions), or where light-dark cycle is not a good predictor of other relevant events in the environment (e.g,. cannot predict rain in very arid regions), or where light cannot penetrate at all (deep ocean, caves, underground burrows). In such organisms the clock may get uncoupled from some of its functions, e.g., it may still time biochemical but not behavioral events. Or the clock may be temporarily or permanently turned off.
Even animals that constantly live in caves still tend to have functioning circadian clocks even if they are not used by these animals to drive rhythms in behavior. In animals that regularly travel into and out of the caves, like bats, the clock is robust.
A number of organisms have been studied in which the clock may temporarily be turned off. In the chestnut tree , circadian clock stops in winter. In reindeer in the high Northern latitudes, behavioral rhythms (and underlying clock) work only during the short springs and autumns, not during the long polar winters and summers. In social insects, castes that spend their time inside the hive and need to work around the clock also do not have a functioning circadian clock.
The organisms that live in extreme environments tend to be difficult to study. It may be a harsh environment for the human researchers to spend long periods of time in. The organisms may not be easy to bring into the lab to study under controlled conditions. Most of such organisms are far from being standard “laboratory models” which means that little is known about their genetics, biochemistry, physiology and behavior.
Thus, one is limited in choices as to which rhythms to study and what conclusions one can take from such studies. A limited number of overt rhythms can be easily monitored in a standardized manner even in the laboratory. A record of overall physical activity and movement is usually made. Additional measured rhythms may be daily fluctuations in hormones, e.g., melatonin. And tissue samples may be taken over a 24-hour period for analysis of patterns of expression of core clock genes.
This approach may miss stuff. For example, even if there is no cycling of clock genes or overt behavioral rhythms, this does not mean that the clock may not be working anyway – cytoplasmatic cellular clocks, or ensembles of neural cells producing weak rhythms, or hormonal feedback loops between endocrine glands could still be producing daily cycles in some aspects of metabolism not identified by the researchers. The adaptive function of the clock is so strong, if nothing else for coordinating internal events, that is is difficult to persuasively and definitively demonstrate that absolutely nothing in the body cycles around a 24-hours cycle.
An important function of the clock is also in measuring changes in daylength – days get longer in spring and shorter during fall. Even environments that have no daily cycles for a while, or no utility in using light-dark cycles, may have strong seasonality, and seasons are another important aspect of the environment related to time. Most organisms use their circadian clocks to measure the changes in daylength through a mechanism called photoperiodism. So even organisms that have no use for daily clocks, may still retain them for their higher-level function of fine-tuning the annual calendar of events.
Domestication also has an effect on circadian clock as one can argue that the lab and the farm are “extreme environments” in some sense. It is well known that many domesticated strains of laboratory mice, rats and nematodes have lost seasonality. Most of our domesticated animals have vastly prolonged breeding seasons – sometimes spanning the entire year, or adding a Fall season to the existing Spring one – compared to their wild relatives. Domestication may be a strong selective force for abandoning seasonality, which reduces the need for a functional circadian clock as well, especially if human care – feeding, defense, etc. – replace the need for the organism to fend for itself in sync with the cycles of nature.
Now a new player is entering this line of research – barley (Hordeum vulgare). Last week, Faure et al, published an open access paper in PNAS showing that strains of barley from Northern Europe have mutations in one of their photoperiodic genes – EARLY MATURITY8 (EAM8) – and that this gene greatly reduces the amplitude of expression of the core circadian clock genes.
As a result, northern varieties of barley can start flowering early and fast in the season, completely ignoring daylength, just following the normal developmental program. At the same time the disrupted clock allows for much longer daily activity of photosynthesis during long summer days, as it does not shut it down before darkness arrives in the evening.
One can imagine how such mutants were prized in the earlier history of the domestication. As humans moved more and more north, only the barley that could be harvested early and produced large yields was valuable. Late harvest may have been too late: humans may have already moved on, driven by hunger, and left the field to be harvested by birds. Or the harvest, being so small and late, would have been used only for consumption (winter is coming – time to brew some beer!) and not for seed for the next year.
Plant circadian clocks are very complex at the molecular level, involving several different feedback loops in expression, some operating in the morning, others in the evening, etc. Importantly, some of the genes involved in photoperiodism and flowering are intricately connected to the clock and may be a part of some of the clock feedback loops. Most of the past research focused on the way clock genes regulate flowering genes. This is an unusual paper in that it discovers the opposite direction – how a gene involved in flowering feeds back on the clock genes and regulates the way the clock works.
What is exciting about this work is that barley is not a difficult organism to do research on. One does not need heroic efforts or expensive Arctic or speleological gear to study it – it is a domesticated plant, easily grown in fields, glasshouses and labs. Furthermore, much of its biology is already well known, including the similarity between its genes and those of Arabidopsis thaliana, the standard model for plant research.
As a number of strains of barley exist, some southern some northern, there is plenty of material to do comparative studies to figure out exactly which genes and processes were involved in the process of domestication – what was selected for as the humans took their crops with them on their northward migrations. This makes barley potentially a useful standard laboratory model for the general studies of evolution under domestication.
Faure, S., Turner, A.S., Gruszka, D., Christodoulou, V., Davis, S.J., von Korff, M. & Laurie, D.A. Mutation at the circadian clock gene EARLY MATURITY 8 adapts domesticated barley (Hordeum vulgare) to short growing seasons, Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1120496109
Since this article came out in The American Scientist in early 1999 (you can read the entire thing here (pdf)) I have read it many times, I used it in teaching, I discussed it in Journal Clubs, and it is a never-ending fascination for me.
Back in the 1950s, Dmitri Konstantinovich Belyaev started an experiment in which he selectively bred Silver Foxes, very carefully, ONLY for their tameness (and “tameness” was defined very rigorously in terms of type and speed of response, distance that triggers aggression, etc.).
What happened really fast in this experiment is that many other traits showed up, seemingly out of nowhere, in the subsequent generations. They started having splotched and piebald coloration of their coats, floppy ears, white tips of their tails and paws. Their body proportions changed. They started barking. They improved on their performance in cognitive experiments. They started breeding earlier in spring, and many of them started breeding twice a year.
Most of the people reacting to this experiment invoked pleiotropy, i.e., how changes in one gene affect expression of many other genes. See this NYT article for instance. However, even while I was reading it for the first time, my mind screamed – development!
And not just development, but more specifically, heterochrony – change in timing of developmental event.
For instance, when the neural crest cells migrate they become melanocytes in the skin – if due to changes in timing they are late to arrive to some distal parts, e.g., paws and tail-tips, those part will be white. Neural crest cells also migrate to become the adrenal medulla – that little part of the body that releases (nor)epinephrine (adrenaline). If fewer of those cells arrive there on time, less the animal will show stress-response later in life.
I always wished I could get a lab, some foxes, an IACUC approval and some money to run these animals through a battery of standard experiments comparing dogs, wild foxes and domesticated foxes on all sorts of parameters of circadian rhythms, photoperiodism (they did change their seasonality patterns of breeding, after all), etc.
The bottom line is that a subtle change in timing of expression of a single developmental gene, something one can select for by choosing one of the traits (in this case a behavioral trait), will affect the change in timing of expression in many other genes. The difference between wild and domesticated foxes may not be in any DNA sequence at all – it could presumably be all epigenetic (seealso). Sequence differences would arise later, as the two populations are not inter-mixing any more (for over 60 years now).
When you put together development, genetics and evolution, you can see that big changes (or, really, any changes at the very beginning of the evolutionary change) in DNA sequence are not necessary for big changes in entire suites of phenotypic traits. But in the 1950s, the bean-bag deterministic genetics was the norm, so the Belyaev experiment was a big jolt to the scientific community in the West (not so much for the Russian evolutionary biologists, though), so we need to look at this experiment through a decent grasp of history.
Now, I’d like to know what is the state of the experiment today. Ten years ago, the project appeared doomed – they had to sell foxes for fur in order to keep going at a small scale. Has this been fixed? Has anyone from the West help finance the continuation of the project? Has anyone in the West acquired some of the foxes and continued with the project? What are the recent developments?
Most people are aware that social insects, like honeybees, have three “sexes”: queens, drones and workers.
Drones are males. Their only job is to fly out and mate with the queen after which they drop dead.
Female larvae fed ‘royal jelly’ emerge as queens. After mating, the young queen takes a bunch of workers with her and sets up a new colony. She lives much longer than other bees and spends her life laying gazillions of eggs continuously around the clock, while being fed by workers.
Female larvae not fed the ‘royal jelly’ emerge as workers.
Workers perform a variety of jobs in the hive. Some are hive-cleaners, some are ‘nurses’ (they feed the larvae), some are queen’s chaperones (they feed the queen), some are guards (they defend the hive and attack potential enemies) and some are foragers (they collect nectar and pollen from flowers and bring it back to the hive).
What most people are not aware of, though, is that there is a regular progression of ‘jobs’ that each worker bee goes through. The workers rotate through the jobs in an orderly fashion. They all start out doing generalized jobs, e.g., cleaning the hive. Then they move up to doing a more specialized job, for instance being a nurse or taking care of the queen. Later, they become guards, and in the end, when they are older, they become foragers – the terminal phase.
This pattern of behavioral development is called “age polyethism” (poly = many, ethism = expression of behavior), or sometimes “temporal polyethism” (image from BeeSpotter):
This developmental progression in behavior is accompanied by changes in brain structure, patterns of neurotransmitter and hormone synthesis and secretion, and patterns of gene expression in the central nervous system.
Some years ago (as in “more than ten years ago”) Gene Robinson and his students started looking at daily patterns of activity in honeybees. The workers in their early stages are doing jobs inside the hive, where it is always dark. They clean the hive, take care of the eggs and pupae, and feed the larvae and the queen around the clock. Each individual bee sometimes works and sometimes sleeps, without any semblance of a 24-hour pattern. Different individuals work and sleep at different, apparently random times. The hive as a whole is thus constantly busy – there is always a large subset of workers performing their duties, day and night.
As they get older, they start doing the jobs, like being guards, that expose them to the outside of the hive, thus to the light-dark and temperature cycles of the outside world.
Finally, the foragers only go out during the daytime and have clear and distinct daily rhythms. Furthermore, the foragers have to consult an internal clock in order to orient towards the Sun in their travels, as well as to be able to communicate the distance and location of flowers to their mates in the hive using the ‘waggle dance’. As bees are social insects, it is difficult to keep individuals in isolation for longer periods of time, but it has been done successfully and, in such studies, foragers exhibit both freerunning (in constant darkness) and entrained (in light-dark cycles) circadian rhythms, while younger workers do not.
In the Robinson lab, then PhD student Dan Toma and postdoc Guy Bloch did much of the early and exciting work on figuring out how the rhythmicity develops in individual worker bees as they pass through the procession of ‘jobs’.
In an early study, they measured levels of expression of mRNA of the core clock gene Period (Per). The gene was expressed at low levels and no visible daily rhythm in early-stage workers, but at much higher levels and in a circadian fashion in foragers.
As the levels of expression were measured crudely – in entire bee brains – it was impossible at the time to be sure which of the two potential mechanisms were operating: 1) the cellular clock did not work until the bee became a forager, or 2) the cellular clocks were working, but different cells were not synchronized with each other, producing a collectively arrhythmic output: both as measured by gene expression of the entire brain and as measured by behavior of the live bee.
Either way, the study showed correlation: the appearance of the functional circadian clock coincided with other changes in the brain structure, brain chemistry and bee behavior. They could not say at the time what causes what, or even if the synchronicity of changes was purely coincidental. They needed to go beyond correlation and for that they needed to experimentally change the timing to see if various processes can be dissociated or if they are tightly bound to each other.
And there is a clever way to do this!
First, they took some hives and removed all the foragers from it. This disrupted the harmony of the division of labor in the hive – too many cleaners and nurses, but nobody is bringing the food home. When that happens, the behavioral development of other workers speeds up dramatically – in almost no time, some nurses and guards develop into foragers. And, lo and behold, the moment they became foragers, they developed rhythms in behavior and rhythms of the Per gene expression in the brain. So, as the development is accelerated, everything about it is accelerated at the same rate: gene expression, brain structure, neurochemistry, and behavioral rhythmicity.
Nice, but then they did something even better. They removed most of the cleaners and nurses from some hives. Again, the balance of the division of labor was disrupted – plenty of food is arriving into the hive but there is not enough bees inside to take care of that food, process it, feed the larvae, etc. What happened then?
Well, some of the foragers went back into the hive and started performing the house-keeping duties instead of flying out and about. And, interestingly, their brain structure and chemistry reverted its development to resemble that of cleaners and nurses. They lost behavioral rhythmicity and started working randomly around the clock. And the rhythm of clock-gene expression disappeared as well.
So, genetic, neural, endocrine, circadian and behavioral changes all go together at all times. Social structure of the colony, through the patterns of pheromones present in the hive, affects the gene expression, brain development and function, and behavior of individual bees. Just like the gene expression and behavioral patterns, the patterns of melatonin synthesis and secretion in honeybee brains is low and arrhythmic in young workers and becomes greater and rhythmic in foragers. With the recent sequencing of the honeybee genome, the potential for future research in honeybee chronobiology looks promising and exciting.
But are these findings generalizable or are they specific to honeybees? How about other species of bees or other social insects, like wasps, ants and termites? Are they the same?
Other species of socials insects have been studied in terms of age polyethism as well. The earliest study I am aware of (let me know if there is an older one) studying behavioral rhythmicity in relation to behavioral development was a 2004 Naturwissenschaften paper by Sharma et al. on harvester ants. In that study, different castes of worker ants exhibited different patterns – some were strongly diurnal, some nocturnal, some had strange shifts in period, and some were arrhythmic. Those with rhythms could entrain to light-dark cycles as well as display freerunning rhythms in constant darkness.
Just last month [April 2009], a new paper on harvester ants came out in BMC Ecology (Open Access). In it, Ingram et al. show that foragers have circadian rhythms (both in constant darkness and entrained to LD cycles) in expression of Period gene (as well as behavioral rhythms), while ants working on tasks inside the hive do not exhibit any rhythms either in clock-gene expression or in behavior, suggesting that the connection between age polyethism and the development of the circadian clock may be a universal property of all social insects.
We know that in humans, night-shift and rotating-shift schedules are bad for health as the body is in the perpetual state of jet-lag: the numerous clocks in our bodies are not synchronized with each other. We have evolved to be diurnal animals, entrained to environmental light cycles and not traveling over many time zones within hours, or working around the clock. Social insects have evolved a different strategy to deal with the potentially ill effects of shift-work: switch off the clock entirely until one develops far enough that time-keeping becomes a requirement.
Yang, L., Qin, Y., Li, X., Song, D., & Qi, M. (2007). Brain melatonin content and polyethism in adult workers of Apis mellifera and Apis cerana (Hym., Apidae) Journal of Applied Entomology, 131 (9-10), 734-739 DOI: 10.1111/j.1439-0418.2007.01229.x
Sharma, V., Lone, S., Goel, A., & Chandrashekaran, M. (2004). Circadian consequences of social organization in the ant species Camponotus compressus.Naturwissenschaften, 91 (8) DOI: 10.1007/s00114-004-0544-6
Ingram, K., Krummey, S., & LeRoux, M. (2009). Expression patterns of a circadian clock gene are associated with age-related polyethism in harvester ants, Pogonomyrmex occidentalis. BMC Ecology, 9 (1) DOI: 10.1186/1472-6785-9-7
Most of the articles and blog posts I read every day are brought to my attention by my friends on Twitter, Google Plus and Facebook, I get some through email notifications, as well as gleaned from ScienceBlogging.org and ScienceSeeker.org science blog aggregators. I then share a LOT of those links to my followers on Twitter, Facebook and Google Plus every day.
Every workday around midnight I post a linkfest on The Network Central to make it easier to see our network posts if you missed them during the day. Khalil and I take turns highlighting the best work by up-and-coming science writers on The SA Incubator blog. Weekly posting of the ever-growing list of posts submitted for the Open Laboratory is another resource. SciAm homepage is also set as a collection of filters – we decide what goes into “Blogs” box, what in the “Latest News” feed, what in the “Science Agenda” on top of the page, and what to collect into “In-Depth Reports” over time.
Now I will also start a weekly collection of links that are “best of the best” of everything I read over a period of a week – not the posts from #SciAmBlogs, but the rest of the Web: other blogs and other media sites. That means a lot of cutting! I mean, I tweet TONS of links every day! Choosing the best will not come easy to me, so this is a good exercise for me as well, and I hope will become a useful resource to you.
I’ll try to do this every Friday, time of day dependent on travel, work, life etc. Let me know in the comments if you have suggestions for formatting, timing, etc.
The Moscow Rules were directives that undercover American intelligence agents allegedly used in the Cold War. The rules were there to increase agent’s chances of making it out safely.
Sometimes, being in academic science can feel like being enemy territory in a cold war. You are often in strange territory (new lab), with many unfamiliar people (other grad students, post-docs, faculty) whose motivations are unclear. You might not trust them completely (especially administrators). There might not be the risk of attempted assassination by having poison injected into you with a specially built umbrella, but there’s enough similarity that the Moscow Rules can still apply…
…“As you well know, some days things just don’t seem to go well when testing whole animal performance. On one of those days out of frustration, fatigue, etc., we simply yelled at an apparent “slacker” lizard in jest. Much to our surprise this seemed to make a difference. We were also aware of the two recent papers for other species of lizards in which sound appeared relevant to behaviors associated with detecting threats. So, we figured what the heck, why not test for such effects systematically. Unlike many of the studies that you and others have performed with anoles, unless we simply can’t get a lizards to run along the racetrack or they appear unhealthy, we include data from all of the individuals rather than subjectively rating the trials for their quantity. Perhaps, some of the gains in speed associated with our yelling were greatest for those individuals that otherwise might have been discarded after receiving a poor subjective quality rating. Of course, we lack a simple way of determining this. Similarly, we have not yet methodically tested for whether expletives are more effective that milder language.”…
Both publications posit that life, at its most abstract, involves a thermodynamic disequilibrium. That is, life involves physical structures that can only maintain their integrity with inputs of energy. These physical structures will require covalent bonds between atoms (to allow nontrivial chemical reactions), so the environment in which life appears must allow such chemistry to occur. Some kind of liquid, but not necessarily water, would therefore also be necessary to enable those reactions. Finally, some molecules in the living system would need to be capable of Darwinian evolution for the life to arise. (Take note, creationist doubters of evolution: it is now a useful part of the definition of life!)
From theory and experiments, both papers argue that life with these traits could evolve under a wide (but definitely limited) range of environments. Carbon-based life on worlds with liquid water might represent a particularly versatile and common set of solutions, but biochemistry could go in many directions even on Earthlike worlds. And on planets and moons where terrestrial life would perish instantly, life based on silicon instead of carbon or liquid hydrocarbons instead of water might thrive…
I always feel awkward when I talk to plastic patients. The simulation mannequins are impressive: their eyes blink, their chests expand as they breathe, they have pulses, they bleed, they burn. A screen monitors vital signs: I administer a pressor and a dipping blood pressure perks up, or I order a beta blocker and a racing heart rate slows. A physician in the next room lends her voice to play the patient, responding to what I do and say. A physician in the same room becomes a tech, relying results of my tests and nudging me through the next steps when I veer off course….
In an important sense, nothing exists until it’s given a name. And in the living world of organisms, names—official, scientific names—are assigned by unique creatures called taxonomists, experts in the minutiae of structure and biology of particular groups of organisms, working according to a strict and arcane body of rules of biological nomenclature. These individuals tend to be specialists—sages of whales, anglerfishes, microscopic worms that live only between the grains of sand on beaches, microscopic algae, purple sulfur bacteria, and everything in between…
Social networks put a number on those weak ties, but we all have weak ties in our meatspace lives. Marche bemoans how we use machines to check out at the grocery store instead of waiting in line with other people to have our purchases rung up by an actual human. But I wonder — even if you were to speak to the woman giving you dirty looks because you were buying a product with a big carbon footprint, can you actually call that a meaningful relationship?
I talk to people all the time — cab drivers, waiters, flight attendants, the guy at the post office, my manicurist, my barista, the boys at the convenience store where I buy my cigarettes, the guy at the newsstand. I am there, in the flesh. Does this mean our connections are any more meaningful than a like or a plus on social media?
Weak ties exist. They’re everywhere. All we have to do to make them meaningful is take the chance to go deeper. This is as true online as it is offline.
…executives and policy-makers love PAFs, and they especially love comparing them across different risk factors. They are nice, solid numbers that make for strong bullet points and eye-grabbing Powerpoint slides. They have a nasty habit of becoming influential well beyond their actual scientific value. I have seen them used as the arbitrators of decisions, lined up on a single graphic that supposedly illustrates the magnitude of different problems. But of course, they do no such thing…
Margie Profet was always a study in sharp contradictions. A maverick thinker remembered for her innocent demeanor, she was a woman who paired running shorts with heavy sweaters year-round, and had a professional pedigree as eccentric as her clothing choices: Profet had multiple academic degrees but no true perch in academe. In the late 1980s and early 1990s, Profet published original theories about female reproduction that pushed the boundaries of evolutionary biology, forcing an entire field to take note. Indeed, back then it was hard not to notice Margie Profet, a vibrant young woman who made a “forever impression” on grade school chums and Harvard Ph.D.s alike. Today, the most salient fact about Profet is her absence. Neither friends, former advisers, publishers, nor ex-lovers has any idea what happened to her or where she is today. Sometime between 2002 and 2005, Profet, who was then in her mid-40s, vanished without a trace…
Animals have a long tradition of being bilaterally symmetrical – that is, of the left side and the right being nearly identical. Sure, there are a few exceptions – the human heart is nearly always farther to the left side, for instance. Snakes and other elongate, limbless animals sometimes stagger their paired organs (gonads, kidneys) so that one is in front of the other, to better fit in their cylindrical bodies. Most snakes have even done away with one of their two lungs. But the basic external body plan, the bones and muscles on the left and the right, are always mirror-images of one another, right?
Sometimes, just hearing that certain chemicals are in food just puts people off. “I think that a lot of people would be really surprised about the precise chemicals that are used to make their favorite foods,” said Dr. Hartings. Take Cool Whip for example. One of its ingredients is polysorbate-60, a chemical that helps give Cool Whip its puffy appearance. Polysorbate-60 moonlights as an ingredient in sexual lubricants like K-Y YOURS+MINE. Our foods contain all kinds of chemicals that have more than one job. Thankfully, one of those jobs is making food delicious.
Imagine a world of two dimensions, a world with no up or down… just across. No climbing, falling, jumping, or ducking… just shimmying and sidling. Welcome to the world of the sea skater.
Sea skaters, or ocean striders, are small bugs. They’re relatives of the pond skaters or water striders that zip spread-eagled across the surface of ponds and lakes. Except they skate over the open ocean, eating plankton at the surface…
Having a scan of your brain is a uniquely odd experience. I had one done once. I was loaded, torpedo-like, into a claustrophobia-inducing, cocoon-like chamber for nearly an hour, the first few terrifying minutes of which I spent desperately trying to recall whether I had actually passed that metal ball-bearing I swallowed when I was a kid. The machines themselves are pretty damn loud, but something about repetitive clunking noises seems to lull me into a state of relaxation, so I spent the majority of my time in the launch chamber trying not to snooze. Honestly, it was all quite enjoyable…
There exists on my hard drive a folder into which I loathe copying files, but only slightly less than I would loathe deleting them all together. It is a folder called “Aborted Manuscripts” and it is this folder which is the source of my shame. It is a graveyard of stupid ideas and of great ones poorly executed, of unfinished cogitations, of journal rejections, of unresponsive colleagues and of frustrating students. It’s a roadmap documenting 15 years of science (read: “me”) not doing what science (read: “me”) is supposed to do – get published…
The bell curve powerfully shapes how we think of human performance: If lots of students or employees happen to show up as extreme outliers — they’re either very good or very bad — we assume they must represent a skewed sample, because only a few people in a truly random sample are supposed to be outliers.
New research suggests, however, that rather than describe how humans perform, the bell curve may actually be constraining how people perform. Minus such constraints, a new paper argues, lots of people are actually outliers.
Human performance, by this account, does not often fit the bell curve or what scientists call a normal distribution. Rather, it is more likely to fit what scientists call a power distribution…
From the diver who finds the body parts, to the forensic specialist who identifies flecks of paint on the victim and the handwriting expert who examines the killer’s notes… What happens behind the yellow tape of one crime scene
EDITOR’S NOTE: The following column contains sophomoric humor and references to the bodily functions of dinosaurs and the size of certain anatomical features of mice, all in the name of science. If this kind of thing offends you, please skip this and go right to Marmaduke. That dog, he cracks us up…
Most visitors to the million-year-old Dachstein Giant Ice Cave prefer to wear standard winter coats during visits to its freezing, icy interior. But for five days the Dachstein cave systems were a temporary lab for a squad of space scientists. Some 50 scientists assembled from three continents to use the UNESCO World Heritage site as a proxy for Mars—a first for the cave system, which normally hosts jazz concerts, modern art exhibits, laser shows, and a steady stream of tourists….
Noon approached on September 1, 1859, and British astronomer Richard Christopher Carrington was busy with his favorite pastime: tracking sunspots, those huge regions of the star darkened by shifts in its magnetic field. He projected the Sun’s image from his viewing device onto a plate of glass stained a “pale straw colour,” which gave him a picture of the fiery globe one inch shy of a foot in diameter…
…Krechetnikov and his graduate student Hans Mayer decided to investigate coffee spilling at a fluid dynamics conference last year when they watched overburdened participants trying to carry their drinks to and fro. They quickly realized that the physics wasn’t simple. Aside from the mechanics of human walking, which depends on a person’s age, health, and gender, there is the highly involved science of liquid sloshing, which depends on a complex interplay of accelerations, torques, and forces. …
…Yes, some speakers are better than others, and a few of the 42 talks I heard were very good. Also, I know I used to commit many of the same sins I witnessed in talks yesterday and the day before, so as I list the problems, I’ll flag my own bad habits (current and former). Based on conversations with my friends, this is not a problem limited to particle physics conferences, much less to physics conferences in general: it’s endemic in science, and perhaps most academic fields…
Spacesuits are poised to go the way of the cell phone – once bulky and cumbersome, researchers are working on making them slim and smart. In the future, astronauts might be wearing specially engineered garments that combine the life-preserving features of a spacesuit with augmented reality technology that could intuit the wearer’s needs…
…Neuroscience is sort of where genetics was 20-30 years ago: The scientific frontier, fascinating to the public, changing the general worldview, raising ethical questions, science fiction’s closest reflection in reality. This has its benefits and its downfalls. There is currently strong general enthusiasm for neuroscience for just these reasons, but because everything ‘neuro’ is so exciting, the risk of media misrepresentation is high and the misuse of neuroscience concepts and terms by pseudo-science is common. …
…Dr. Johnson says cells from fetal boys and girls have been found in mothers “four to five decades following the last pregnancy.” That fetus may have grown into a middle aged pharmacist, and still his cells are inside his mother. Cells wouldn’t persist in foreign body for NO reason. They must be doing something, but what?…
…what brings many students into anthropology, and still impassions me about the field, is that it does approach the question of “What does it mean to be human?” in the broadest, most interdisciplinary way. And it strikes me that we have some core analytical approaches to that question that matter, and that this style of thinking is what really makes up the holism of anthropology, rather than a particular commitment to four-fields and working across the different sub-disciplines. This human lens includes a comparative approach, an attention to variation across time and space, a recognition that we as researchers inevitably bias our own data, and, yes, a commitment to drawing on multiple strands of research…
There are 94 naturally occurring elements, from Hydrogen to Plutonium, and together they make up everything in the world. The stories of the elements are the stories of our own lives, revealing the details of our personal lives, the patterns of our economies, and our relationships with our natural resources.
94 Elements is a new global filmmaking project, exploring our lives through the lens of the elements. The project is producing a collection of stories by different filmmakers about the endless ways the elements touch our daily lives. Each filmmaker takes one element as the basis for a film around how it’s used. The films are surprising and moving human stories – this is not about science, but about our human relationships with our mineral resources.
Each prescription drug you take has a unique code that the government can use to track problems. But artificial hips and pacemakers? They are implanted without identification, along with many other medical devices. In fact, the FDA doesn’t know how many devices are implanted into patients each year – it simply doesn’t track that data.
The past decade has seen numerous high profile cases of malfunctioning medical devices, which have led to injury or even death. Critics say the FDA’s minimal monitoring of devices contributes to these problems….
As long as leptin levels stay within normal levels, all of the functions displayed above function normally. As the leptin levels drop, many of these functions are adversely effected. It is a wide-spread trigger for a starvation response. Why cripple the immune response during starvation? My best guess would be because of the huge energy expenditure required to keep the immune response running normally, especially in cellular proliferation.
New US findings suggest our accepted definition of a healthy vagina could be ethnically biased, say some researchers, but others caution against over-interpreting the data.
A new study published today in Science Translational Medicine found, what an accompanying commentary describes as, an “unexpected and astonishing” variability over time in the vaginal bacterial communities of apparently healthy women….
…A record number of people are depending on federally financed food assistance. Food-stamp use increased from an average monthly caseload of 17 million in 2000 to 44 million people in 2011, according to the U.S. Department of Agriculture’s Web site. Last year, one in six people—almost 50 million Americans, or 15 percent of the population—received food stamps.
Ms. Bruninga-Matteau is part of an often overlooked, and growing, subgroup of Ph.D. recipients, adjunct professors, and other Americans with advanced degrees who have had to apply for food stamps or some other form of government aid since late 2007….
…Because his secondary crusade of the last few years, you know, the one against evil industrial chemicals, is really starting to annoy me. This is not saying that he’s entirely wrong – there are evil industrial chemicals out there. And, in many cases, they aren’t as well researched or as well regulated as they should be.
But if we, as journalists, are going to demand meticulous standards for the study and oversight of chemical compounds then we should try to be meticulous ourselves in making the case. And much as I would like it to be otherwise, I don’t see enough of that in Kristof’s chemical columns. They tend instead to be sloppy in their use of language, less than thorough, and chemophobic enough to undermine his legitimate points….
Scholars and pundits alike argue that U.S. scientists could do more to reach out to the general public. Yet, to date, there have been few systematic studies that examine how scientists understand the barriers that impede such outreach. Through analysis of 97 semi-structured interviews with academic biologists and physicists at top research universities in the United States, we classify the type and target audiences of scientists’ outreach activities. Finally, we explore the narratives academic scientists have about outreach and its reception in the academy, in particular what they perceive as impediments to these activities. We find that scientists’ outreach activities are stratified by gender and that university and disciplinary rewards as well as scientists’ perceptions of their own skills have an impact on science outreach. Research contributions and recommendations for university policy follow.
…So, to recap, 1) Cool paper. 2) Sex between blue-eyed people is not incest. 3) We have no idea when or where this mutation came from, but it is now conceivable that we could ask the question. 4) Embarrassingly bad science reporting spontaneously rises from the grave four years later and tries to eat your brain.
There is no substitute for direct replication – if you cannot reproduce the same result using the same methods then you cannot have a cumulative science. But conceptual replication also has a very important role to play in psychological science. What is conceptual replication? It’s when instead of replicating the exact same experiment in exactly the same way, we test the experiment’s underlying hypothesis using different methods…
Another reason conceptual replication is so important is that if the field relies exclusively on direct replication then they risk replicating the same mistakes as well. Today I wanted to illustrate this risk by looking back at the history of one of social psychology’s most influential theories: cognitive dissonance. The richness and depth of Cognitive Dissonance Theory is a result of dozens of conceptual replications. I suggest that, had it not been for conceptual replication – had dissonance only been tested and re-tested in the original paradigm (Brehm’s Free Choice Paradigm) – the theory may not have stood up to recent criticisms directed at that particular paradigm…
As many as 900 dolphins and over 4,000 pelicans have washed up dead on the beaches of northern Peru in the last couple of months, (see news coverage here, here and here), leading to a flurry of activity as various authorities and other interested parties move to find out what is going on. Experts cited in the news coverage suggest that unusually warm surface waters (10F higher than the season average) are changing the swimming patterns of the huge anchovetta schools off the coast of Peru, driving them deeper and out of the diving range of pelicans. In other words, the pelicans appear to be starving. The dolphins on the other hand, have shown a high prevalence of infection with morbilivirus, which is an infectious disease…
A sperm cell, much like an expensive robotic vacuum cleaner, is a minimally intelligent body on a mission. Both the Roomba and the male gamete have to navigate a walled space without much idea where they’re going or why. And although it won’t clean your floors on the way, the sperm cell uses some of the same strategy as the robot vacuum…
Naturally a mother bat is happy to welcome into the world a bouncing baby whatever, as long as it has all its fingers and toe-claws. But she also wants her little one to have every advantage she can give it. So when spring comes early, big brown bats prefer to keep their female embryos. Unwanted males are reabsorbed into their mothers’ bodies as if they never existed…
…By now, readers understand that the definitive “copy” of any article is no longer the one on paper but the online copy, precisely because it’s the version that’s been read and mauled and annotated by readers. (If a book isn’t read until it’s written in — as I was always told — then maybe an article is not published until it’s been commented upon.) Writers know this already. The print edition of any article is little more than a trophy version, the equivalent of a diploma or certificate of merit — suitable for framing, not much else.
We call the fallout to any article the “comments,” but since they are often filled with solid arguments, smart corrections and new facts, the thing needs a nobler name. Maybe “gloss.” In the Middle Ages, students often wrote notes in the margins of well-regarded manuscripts. These glosses, along with other forms of marginalia, took on a life of their own, becoming their own form of knowledge, as important as, say, midrash is to Jewish scriptures. The best glosses were compiled into, of course, glossaries and later published — serving as some of the very first dictionaries in Europe.
Any article, journalistic or scientific, that sparks a debate typically winds up looking more like a good manuscript 700 years ago than a magazine piece only 10 years ago. The truth is that every decent article now aspires to become the wiki of its own headline. …
..We might be hard put to find any area of science coverage that hasn’t been subject to those kinds of distortions. Coverage of Lipitor and its ilk was certainly as likely to contain dramatic headlines, and particular agendas, including those of pharmaceutical companies. And ideological arguments? It depends upon what the meaning of “ideological” is…
From advice about “exercising your mind” to treatises on “the gay brain,” media coverage of neuroscience in the UK often pushes “thinly disguised ideological arguments” and reinforces artificial divisions between social groups, according to a new study….
…In the past several years, we’ve all heard readers mourn the passing of the printed word. The elegy is familiar: I crave the smell of a well-worn book, the weight of it in my hands; all of my favorite books I discovered through loans from a friend, that minor but still-significant ritual of trust; I need to see it on my shelf after I’ve read it (and I don’t mind if others see it too); and what is a classic if not a book where I’m forced to rediscover my own embarrassing college-age marginalia?
Luddites can take comfort in the persistence of vinyl records, postcards, and photographic film. The paper book will likewise survive, but its place in the culture will change significantly. As it loses its traditional value as an efficient vessel for text, the paper book’s other qualities—from its role in literary history to its inimitable design possibilities to its potential for physical beauty—will take on more importance. The future is yet to be written, but a few possibilities for the fate of the paper book are already on display on bookshelves near you…
…He expected — and banked on — the web’s virality, he says; he didn’t anticipate, though, how eagerly that web’s self-defined news sources would pass along his “discovery.” And he assumed people would figure out the story’s hoaxiness much more quickly than they actually did — and, then, that the corrective powers of the social web would make that joke clear within the first hour or so after the story went live…
…Berners-Lee said he was concerned about how increased demands for monitoring the web, both from governments looking for greater powers to track down terrorists and companies looking to trade our personal web data for commercial purposes, threatens the very infrastructure of the web.
He described his worry that people in the end will no longer trust and use the web for e.g. researching sensitive things like depression if they fear everything they do online is being monitored…
One of today’s most challenging yet promising markets is the educational system. If you want to see startups hungry to disrupt an industry, look no further. Founders are trying to solve the problems plaguing our education system: including reconciling student debt, providing students with the skills required to land a job both before and after graduation, and offering the best course material online regardless of age, location and educational level…
One topic we neglected, however, was what current medical students can do right now to get their foot in the door and begin engaging in the social media and medicine conversation. I had hoped to get to this topic during my panel discussion, but there just weren’t enough hours to cover everything. Below is my attempt to remedy this omission. Here are a few simple things you can do:
Imagine a situation where homes had no kitchens and utensils were unavailable. We would all be dependent on cafes and restaurants to eat and, it follows, our idea of what it is to prepare food would be exhausted by those working in such a capacity within these establishments. Now introduce kitchens into homes and affordable utensils into shops. Suddenly we can cook meals at home. Obviously the quality of the infrastructure is lower and there’s less expertise. For the sake of the thought-experiment, assume kitchens and utensils appeared suddenly, to an extent profoundly disruptive of established practices of going out for every meal. The meals cooked at home would be of poor quality, probably pragmatically orientated and often imitating (poorly) the meals available in restaurants and cafes.
Mr. McDonald said The Times currently has 1,500 advance obits in the can – “and we’re adding about 250 a year. Even if you subtract the number of those we’ll publish in a given year – say, 50 – the archive is growing significantly.”…
….The nice way to say this is that selects for pundits who have a thick skin—or forces them to quickly develop one. The less nice way to say it is that it forces you to stop giving a shit what other people think. Maybe not universally——you’ll pick out a domain of people whose criticisms are allowed to slip through the armor—but by default….
…The most popular sentence of the whole session was “Don’t underestimate your audience’s intelligence, but do underestimate their vocabulary.” In other words, drop the jargon if you want the public to get what you’re saying. …
…In the face of such a flood of information, no-one can read everything that’s made it through the filters into all their favourite journals. So in practice what actually happens is that each of us filters again – finding relevant publications in a huge range of journals by the social web we’re in: mailing lists, blogs, Twitter, and so on. I believe some people even use FaceBo