Category Archives: Science News

My picks from ScienceDaily

Bats Play A Major Role In Plant Protection:

If you get a chance to sip some shade-grown Mexican organic coffee, please pause a moment to thank the bats that helped make it possible. At Mexican organic coffee plantations, where pesticides are banned, bats and birds work night and day to control insect pests that might otherwise munch the crop.


Animals Are ‘Stuck In Time’ With Little Idea Of Past Or Future, Study Suggests:

Dog owners, who have noticed that their four-legged friend seem equally delighted to see them after five minutes away as five hours, may wonder if animals can tell when time passes. Newly published research from The University of Western Ontario may bring us closer to answering that very question.

Birdfeeders Can Both Help And Harm Bird Populations:

Millions of people tend bird feeders in their backyards each year, often out of a desire to help the animals. But a new survey of research on the topic finds that feeding may not always bring a positive outcome for the birds.

Alligator Blood May Put The Bite On Antibiotic-resistant Infections:

Despite their reputation for deadly attacks on humans and pets, alligators are wiggling their way toward a new role as potential lifesavers in medicine, biochemists in Louisiana reported at the 235th national meeting of the American Chemical Society. They described how proteins in gator blood may provide a source of powerful new antibiotics to help fight infections associated with diabetic ulcers, severe burns, and “superbugs” that are resistant to conventional medication.

High-flying Moths Don’t Just Go With The Flow:

Enormous numbers of migratory moths that fly high above our heads throughout the night aren’t at the mercy of the winds that propel them toward their final destinations, researchers report online on April 3rd in Current Biology. Rather, they rely on sophisticated behaviors to control their flight direction, and to speed their long-distance journeys into areas suitable for the next generation of moths.

First Lungless Frog Discovered:

Researchers have confirmed the first case of complete lunglessness in a frog, according to a report in the April 8th issue of Current Biology, a publication of Cell Press. The aquatic frog Barbourula kalimantanensis apparently gets all the oxygen it needs through its skin.

Darwin Was Right: Natural Selection Speeds Up Speciation:

In the first experiment of its kind conducted in nature, a University of British Columbia evolutionary biologist has come up with strong evidence for one of Charles Darwin’s cornerstone ideas — adaptation to the environment accelerates the creation of new species.

My picks from ScienceDaily

Go at it! These are sooooo….bloggable ;-)
Computer Taught To Recognize Attractiveness In Women:

“Beauty,” goes the old saying, “is in the eye of the beholder.” But does the beholder have to be human? Not necessarily, say scientists at Tel Aviv University. Amit Kagian, an M.Sc. graduate from the TAU School of Computer Sciences, has successfully “taught” a computer how to interpret attractiveness in women. But there’s a more serious dimension to this issue that reaches beyond mere vanity. The discovery is a step towards developing artificial intelligence in computers. Other applications for the software could be in plastic and reconstructive surgery and computer visualization programs such as face recognition technologies.

Irrelevant Image Of Attractive Woman Can Make A Man More Willing To Take Big Financial Risks:

Attractive women plus cool cars equal brisk sales for auto dealers as men snap up those cars, prompted–or so advertising theory goes–by the association. But is the human male really so easily swayed? Can the irrelevant image of an alluring female posing by the merchandise actually encourage a heterosexual man to purchase it?

People Accept Anger In Men, But Women Who Lose Their Temper Are Seen As Less Competent, Study Shows:

Whether you are running for president or looking for a clerical job, you cannot afford to get angry if you are a woman, Yale University psychologist Victoria Brescoll has found. Brescoll and Eric Uhlmann at Northwestern University recently completed three separate studies to explore a phenomenon that may be all-too-familiar to women like New York Senator Hillary Clinton: People accept and even reward men who get angry but view women who lose their temper as less competent.

Why Do Rats Die Younger Than Humans? Newly Discovered Biological Clock Provides Tantalizing Clues:

A New York University dental professor has discovered a biological clock linking tooth growth to other metabolic processes. This clock, or biological rhythm, controls many metabolic functions and is based on the circadian rhythm, which is a roughly 24-hour cycle that is important in determining sleeping and feeding patterns, cell regeneration, and other biological processes in mammals. The newly discovered rhythm, like the circadian rhythm, originates in the hypothalamus, a region of the brain that functions as the main control center for the autonomic nervous system. But unlike the circadian rhythm, this clock varies from one organism to another, operating on shorter time intervals for small mammals, and longer ones for larger animals. For example, rats have a one-day interval, chimpanzees six, and humans eight.

Coral Reefs And Climate Change: Microbes Could Be The Key To Coral Death:

Coral reefs could be dying out because of changes to the microbes that live in them just as much as from the direct rise in temperature caused by global warming, according to scientists speaking April 2, 2008 at the Society for General Microbiology’s 162nd meeting.

My picks from ScienceDaily

Exactly How Much Housework Does A Husband Create?:

Having a husband creates an extra seven hours a week of housework for women, according to a University of Michigan study of a nationally representative sample of U.S. families. For men, the picture is very different: A wife saves men from about an hour of housework a week.

The figure included in the article states something quite different, see what Larry says about it.
Fossil From Last Common Ancestor Of Neanderthals And Humans Found In Europe, 1.2 Million Years Old:

University of Michigan researcher Josep M. Pares is part of a team that has discovered the oldest known remains of human ancestors in Western Europe.

Habitat Destruction May Wipe Out Monarch Butterfly Migration:

Intense deforestation in Mexico could ruin one of North America’s most celebrated natural wonders — the mysterious 3,000-mile migration of the monarch butterfly. According to a University of Kansas researcher, the astonishing migration may collapse rapidly without urgent action to end devastation of the butterfly’s vital sources of food and shelter.

Is DNA Repair A Substitute For Sex?:

Birds and bees may do it, but the microscopic animals called bdelloid rotifers seem to get along just fine without sex, thank you. What’s more, they have done so over millions of years of evolution, resulting in at least 370 species. These hardy creatures somehow escape the usual drawback of asexuality – extinction – and the MBL’s David Mark Welch, Matthew Meselson, and their colleagues are finding out how.

Feathered Friends Favor Fruity Flavonoids:

Fruit-eating birds actively select fruit with the highest concentrations of antioxidants — compounds that help them maintain a healthy immune system — ecologists have found. This is the first time that a group of antioxidants known as flavonoids have been found to boost the immune system in studies on living animals, as opposed to test-tube studies.

Female Veterinarians At Risk Of Miscarriage From Anesthetic Gases And Pesticides, Study Suggests:

Female vets run twice the risk of miscarriage as a result of exposure to anaesthetic gases and pesticides, suggests a study published ahead of print in Occupational and Environmental Medicine.

My picks from ScienceDaily

Good Sexual Intercourse Lasts Minutes, Not Hours, Therapists Say:

Satisfactory sexual intercourse for couples lasts from 3 to 13 minutes, contrary to popular fantasy about the need for hours of sexual activity, according to a survey of U.S. and Canadian sex therapists.

Mouse Calls During Courtship Help Search For Emotion-controlling Genes:

Scientists have long known that emotions and other personality traits and disorders run together in families. But finding which genes are most important in controlling emotions has proven difficult. Humans and mice have similar numbers of genes, but mice are valuable because their genes can be deleted or added. Many researchers have begun to study mouse behaviors to try to link genes with complex behaviors. A new study found that male mice make high-frequency vocalizations during sexual interactions with female mice. These high-frequency calls are associated with approach behaviours, and with genes that control positive emotions.

The Untrained Eye: Confusing Sexual Interest With Friendliness:

New research from Indiana University and Yale suggests that college-age men confuse friendly non-verbal cues with cues for sexual interest because the men have a less discerning eye than women — but their female peers aren’t far behind.

The Lean Gene: Thinness Is An Inheritable Trait:

Your friend can eat whatever she wants and still fit into her prom dress, but you gain five pounds if you just look at that chocolate cake. Before you sign up for Weight Watchers and that gym membership, though, you may want to look at some recent research from Tel Aviv University and save yourself a few hundred dollars.

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New and Exciting in PLoS ONE

There are 47 articles published in PLoS ONE this week. Here are some of the coolest titles – you go and find your own.
Ultrasonic Vocalizations Induced by Sex and Amphetamine in M2, M4, M5 Muscarinic and D2 Dopamine Receptor Knockout Mice:

Adult mice communicate by emitting ultrasonic vocalizations (USVs) during the appetitive phases of sexual behavior. However, little is known about the genes important in controlling call production. Here, we study the induction and regulation of USVs in muscarinic and dopaminergic receptor knockout (KO) mice as well as wild-type controls during sexual behavior. Female mouse urine, but not female rat or human urine, induced USVs in male mice, whereas male urine did not induce USVs in females. Direct contact of males with females is required for eliciting high level of USVs in males. USVs (25 to120 kHz) were emitted only by males, suggesting positive state; however human-audible squeaks were produced only by females, implying negative state during male-female pairing. USVs were divided into flat and frequency-modulated calls. Male USVs often changed from continuous to broken frequency-modulated calls after initiation of mounting. In M2 KO mice, USVs were lost in about 70-80% of the mice, correlating with a loss of sexual interaction. In M5 KO mice, mean USVs were reduced by almost 80% even though sexual interaction was vigorous. In D2 KOs, the duration of USVs was extended by 20%. In M4 KOs, no significant differences were observed. Amphetamine dose-dependently induced USVs in wild-type males (most at 0.5 mg/kg i.p.), but did not elicit USVs in M5 KO or female mice. These studies suggest that M2 and M5 muscarinic receptors are needed for male USV production during male-female interactions, likely via their roles in dopamine activation. These findings are important for the understanding of the neural substrates for positive affect.

Maternal Cocaine Administration in Mice Alters DNA Methylation and Gene Expression in Hippocampal Neurons of Neonatal and Prepubertal Offspring:

Previous studies documented significant behavioral changes in the offspring of cocaine-exposed mothers. We now explore the hypothesis that maternal cocaine exposure could alter the fetal epigenetic machinery sufficiently to cause lasting neurochemical and functional changes in the offspring. Pregnant CD1 mice were administered either saline or 20 mg/kg cocaine twice daily on gestational days 8-19. Male pups from each of ten litters of the cocaine and control groups were analyzed at 3 (P3) or 30 (P30) days postnatum. Global DNA methylation, methylated DNA immunoprecipitation followed by CGI2 microarray profiling and bisulfite sequencing, as well as quantitative real-time RT-PCR gene expression analysis, were evaluated in hippocampal pyramidal neurons excised by laser capture microdissection. Following maternal cocaine exposure, global DNA methylation was significantly decreased at P3 and increased at P30. Among the 492 CGIs whose methylation was significantly altered by cocaine at P3, 34% were hypermethylated while 66% were hypomethylated. Several of these CGIs contained promoter regions for genes implicated in crucial cellular functions. Endogenous expression of selected genes linked to the abnormally methylated CGIs was correspondingly decreased or increased by as much as 4-19-fold. By P30, some of the cocaine-associated effects at P3 endured, reversed to opposite directions, or disappeared. Further, additional sets of abnormally methylated targets emerged at P30 that were not observed at P3. Taken together, these observations indicate that maternal cocaine exposure during the second and third trimesters of gestation could produce potentially profound structural and functional modifications in the epigenomic programs of neonatal and prepubertal mice.

Ecological Niche Dimensionality and the Evolutionary Diversification of Stick Insects:

The degree of phenotypic divergence and reproductive isolation between taxon pairs can vary quantitatively, and often increases as evolutionary divergence proceeds through various stages, from polymorphism to population differentiation, ecotype and race formation, speciation, and post-speciational divergence. Although divergent natural selection promotes divergence, it does not always result in strong differentiation. For example, divergent selection can fail to complete speciation, and distinct species pairs sometimes collapse (‘speciation in reverse’). Widely-discussed explanations for this variability concern genetic architecture, and the geographic arrangement of populations. A less-explored possibility is that the degree of phenotypic and reproductive divergence between taxon pairs is positively related to the number of ecological niche dimensions (i.e., traits) subject to divergent selection. Some data supporting this idea stem from laboratory experimental evolution studies using Drosophila, but tests from nature are lacking. Here we report results from manipulative field experiments in natural populations of herbivorous Timema stick insects that are consistent with this ‘niche dimensionality’ hypothesis. In such insects, divergent selection between host plants might occur for cryptic colouration (camouflage to evade visual predation), physiology (to detoxify plant chemicals), or both of these niche dimensions. We show that divergent selection on the single niche dimension of cryptic colouration can result in ecotype formation and intermediate levels of phenotypic and reproductive divergence between populations feeding on different hosts. However, greater divergence between a species pair involved divergent selection on both niche dimensions. Although further replication of the trends reported here is required, the results suggest that dimensionality of selection may complement genetic and geographic explanations for the degree of diversification in nature.

Mesoscopic Structure Conditions the Emergence of Cooperation on Social Networks:

We study the evolutionary Prisoner’s Dilemma on two social networks substrates obtained from actual relational data. We find very different cooperation levels on each of them that cannot be easily understood in terms of global statistical properties of both networks. We claim that the result can be understood at the mesoscopic scale, by studying the community structure of the networks. We explain the dependence of the cooperation level on the temptation parameter in terms of the internal structure of the communities and their interconnections. We then test our results on community-structured, specifically designed artificial networks, finding a good agreement with the observations in both real substrates. Our results support the conclusion that studies of evolutionary games on model networks and their interpretation in terms of global properties may not be sufficient to study specific, real social systems. Further, the study allows us to define new quantitative parameters that summarize the mesoscopic structure of any network. In addition, the community perspective may be helpful to interpret the origin and behavior of existing networks as well as to design structures that show resilient cooperative behavior.

The Airborne Metagenome in an Indoor Urban Environment:

The indoor atmosphere is an ecological unit that impacts on public health. To investigate the composition of organisms in this space, we applied culture-independent approaches to microbes harvested from the air of two densely populated urban buildings, from which we analyzed 80 megabases genomic DNA sequence and 6000 16S rDNA clones. The air microbiota is primarily bacteria, including potential opportunistic pathogens commonly isolated from human-inhabited environments such as hospitals, but none of the data contain matches to virulent pathogens or bioterror agents. Comparison of air samples with each other and nearby environments suggested that the indoor air microbes are not random transients from surrounding outdoor environments, but rather originate from indoor niches. Sequence annotation by gene function revealed specific adaptive capabilities enriched in the air environment, including genes potentially involved in resistance to desiccation and oxidative damage. This baseline index of air microbiota will be valuable for improving designs of surveillance for natural or man-made release of virulent pathogens.

Inevitable Evolutionary Temporal Elements in Neural Processing: A Study Based on Evolutionary Simulations:

Recent studies have suggested that some neural computational mechanisms are based on the fine temporal structure of spiking activity. However, less effort has been devoted to investigating the evolutionary aspects of such mechanisms. In this paper we explore the issue of temporal neural computation from an evolutionary point of view, using a genetic simulation of the evolutionary development of neural systems. We evolve neural systems in an environment with selective pressure based on mate finding, and examine the temporal aspects of the evolved systems. In repeating evolutionary sessions, there was a significant increase during evolution in the mutual information between the evolved agent’s temporal neural representation and the external environment. In ten different simulated evolutionary sessions, there was an increased effect of time -related neural ablations on the agents’ fitness. These results suggest that in some fitness landscapes the emergence of temporal elements in neural computation is almost inevitable. Future research using similar evolutionary simulations may shed new light on various biological mechanisms.

My picks from ScienceDaily

Climate Change And Human Hunting Combine To Drive The Woolly Mammoth Extinct:

Does the human species have mammoth blood on its hands? Scientists have long debated the relative importance of hunting by our ancestors and change in global climate in consigning the mammoth to the history books. A new paper uses climate models and fossil distribution to establish that the woolly mammoth went extinct primarily because of loss of habitat due to changes in temperature, while human hunting acted as the final straw.

Anne-Marie, Kambiz and artificialhabitat have more.
Study Questions ‘Cost Of Complexity’ In Evolution

Higher organisms do not have a “cost of complexity” — or slowdown in the evolution of complex traits — according to a report by researchers at Yale and Washington University in Nature. Biologists have long puzzled over the relationship between evolution of complex traits and the randomness of mutations in genes. Some have proposed that a “cost of complexity” makes it more difficult to evolve a complicated trait by random mutations, because effects of beneficial mutations are diluted.

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New and Exciting in PLoS Medicine and PLoS Biology

Climate Change, Humans, and the Extinction of the Woolly Mammoth:

What caused the woolly mammoth’s extinction? Climate warming in the Holocene might have driven the extinction of this cold-adapted species, yet the species had survived previous warming periods, suggesting that the more-plausible cause was human expansion. Testing these competing hypotheses has been hampered by the difficulty in generating quantitative estimates of the relationship between the mammoth’s contraction and the climatic and/or human-induced drivers of extinction. In this study, we combined paleo-climate simulations, climate envelope models (which describe the climate associated with the known distribution of a species–its envelope–and estimate that envelope’s position under different climate change scenarios), and a population model that includes an explicit treatment of woolly mammoth-human interactions to measure the extent to which climate changes, increased human pressures, or a combination of both factors might have been responsible. Results show a dramatic decline in suitable climate conditions for the mammoth between the Late Pleistocene and the Holocene, with hospitable areas in the mid-Holocene being restricted mainly to Arctic Siberia, where the latest records of woolly mammoths in continental Asia have been found. The population model results also support the view that the collapse of the climatically suitable area caused a significant drop in mammoth population size, making the animals more vulnerable to increasing hunting pressure from expanding human populations. The coincidence of the collapse of climatically suitable areas and the increase in anthropogenic impacts in the Holocene are most likely to have been the “coup de grâce,” which set the place and time for the extinction of the woolly mammoth.

What Killed the Woolly Mammoth?:

Forty-two thousand years ago, during the last glacial advance of the Pleistocene epoch, woolly mammoths thundered across the frozen steppes of the Eurasian continent. The huge beasts thrived on the arid tundra of the last ice age, having adapted to temperatures that would chill the toes off any hairless ape. Yet, by the middle of the Holocene epoch, 6,000 years ago, the glaciers had retreated and the Eurasian woolly mammoth was on the verge of extinction. They were ultimately done in, say David Nogués-Bravo and colleagues, by climate change–with a helping hand from humans.

Exposure to War as a Risk Factor for Mental Disorders:

While large-scale national psychiatric epidemiologic studies have been conducted in Western industrialized nations [1-3], studies in the Arab world have generally been limited to smaller populations [4-6]. In addition, while exposure to war as a risk factor for the development of mental disorders in military populations has previously been described [7,8], the effect of war upon first onset of a range of mental disorders in civilian populations at a national level has not been explored.

Chile’s Neoliberal Health Reform: An Assessment and a Critique:

* The Chilean health system underwent a drastic neoliberal reform in the 1980s, with the creation of a dual system: public and private health insurance and public and private provision of health services.
* This reform served as a model for later World Bank-inspired reforms in countries like Colombia.
* The private part of the Chilean health system, including private insurers and private providers, is highly inefficient and has decreased solidarity between rich and poor, sick and healthy, and young and old.
* In spite of serious underfinancing during the Pinochet years, the public health component remains the backbone of the system and is responsible for the good health status of the Chilean population.
* The Chilean health reform has lessons for other countries in Latin America and elsewhere: privatisation of health insurance services may not have the expected results according to neoliberal doctrine. On the contrary, it may increase unfairness in financing and inequitable access to quality care.

Chromosomal Gene Movements Reflect the Recent Origin and Biology of Therian Sex Chromosomes:

Our sex chromosomes have profoundly differentiated since evolving from an ancestral pair of non-sex chromosomes (autosomes). In this study, we first show that X chromosome-derived retrogenes (genes that arose as duplicates of “parental” X-linked genes) are specifically expressed during the meiotic and postmeiotic stages of spermatogenesis, thus functionally replacing their parents during, but also after, the process of male meiotic sex chromosome inactivation (MSCI). We then show that the “export” of retroposed gene copies from the X chromosome started rather recently during mammalian evolution, on the eutherian (“placental” mammal) and marsupial lineages, respectively. This suggests that MSCI–the main driving force for this out of the X gene “movement”–originated around the separation of these two major (therian) mammalian lineages, approximately 180 million years ago. Given that MSCI was likely triggered as soon as the proto-X and -Y chromosomes ceased to recombine (an event that marks the origin of these sex chromosomes), our data also support the recent notion that our sex chromosomes and those of other therians emerged, not in the common ancestor of all mammals, but–probably rather late–in the therian ancestor.

My picks from ScienceDaily

Teenaged Dome-skulled Dinosaurs Could Really Knock Heads, Virtual Smash-ups Show:

After half a century of debate, a University of Alberta researcher has confirmed that dome-headed dinosaurs called pachycephalosaurs could collide with each other during courtship combat. Eric Snively, an Alberta Ingenuity fellow at the U of A, used computer software to smash the sheep-sized dinosaurs together in a virtual collision and results showed that their bony domes could emerge unscathed.

Squid Beak Is Both Hard And Soft, A Material That Engineers Want To Copy:

How did nature make the squid’s beak super hard and sharp —- allowing it, without harm to its soft body —- to capture its prey? The question has captivated those interested in creating new materials that mimic biological materials. The results are published in the journal Science.

Sensors For Bat-inspired Spy Plane Under Development:

A six-inch robotic spy plane modeled after a bat would gather data from sights, sounds and smells in urban combat zones and transmit information back to a soldier in real time.

Hormone That Controls Hunger And Appetite Also Linked To Reduced Fertility:

Researchers at Yale School of Medicine have found that in-utero exposure to the hormone grhelin, a molecule that controls appetite and hunger and nutrition, can result in decreased fertility and fewer offspring. Ghrelin, the so-called “hunger hormone,” is produced in the stomach and brain, induces food intake, and operates through a brain region that controls cravings for food and other energy sources. Ghrelin decreases the HOXA 10 gene that is involved in developmental programming of the uterus. The HOXA 10 gene determines how the uterus will develop in adulthood.

Small Desert Beetle Found To Engineer Ecosystems:

The catastrophic action a tiny beetle is wreaking on the deteriorating Chihuahuan desert will be revealed in the April edition of the Royal Entomological Society’s Ecological Entomology journal.

Armed Beetles Find A Mate, Whatever Their Size:

One species of armed beetle is proving that size doesn’t necessarily matter when it comes to finding a mate. The creature uses what might be considered rather persuasive ‘pulling techniques.’

My picks from ScienceDaily

American West Heating Nearly Twice As Fast As Rest Of World, New Analysis Shows:

The American West is heating up more rapidly than the rest of the world, according to a new analysis of the most recent federal government temperature figures. The news is especially bad for some of the nation’s fastest growing cities, which receive water from the drought-stricken Colorado River. The average temperature rise in the Southwest’s largest river basin was more than double the average global increase, likely spelling even more parched conditions.

Are You What You Eat? New Study Of Body Weight Change Says Maybe Not:

If identical twins eat and exercise equally, must they have the same body weight” By analyzing the fundamental equations of body weight change, NIH investigators Carson Chow and Kevin Hall find that identical twins with identical lifestyles can have different body weights and different amounts of body fat.

Appendix Removed Through Vagina: U.S. First:

On March 26, 2008, surgeons at UC San Diego Medical Center removed an inflamed appendix through a patient’s vagina, a first in the United States. Following the 50-minute procedure, the patient, Diana Schlamadinger, reported only minor discomfort. Removal of diseased organs through the body’s natural openings offers patients a rapid recovery, minimal pain, and no scarring. Key to these surgical clinical trials is collaboration with medical device companies to develop new minimally-invasive tools.

Teenage Risk-taking: Teenage Brains Really Are Different From Child Or Adult Brains:

Many parents are convinced that the brains of their teenage offspring are different than those of children and adults. New data confirms that this is the case. An article by Jay N. Giedd, MD, of the National Institute of Mental Health (NIMH), published in Journal of Adolescent Health describes how brain changes in the adolescent brain impact cognition, emotion and behavior.

Who’s Bad? Chimps Figure It Out By Observation:

Chimpanzees make judgments about the actions and dispositions of strangers by observing others’ behavior and interactions in different situations. Specifically, chimpanzees show an ability to recognize certain behavioral traits and make assumptions about the presence or absence of these traits in strangers in similar situations thereafter. These findings are by Dr. Francys Subiaul – from the George Washington University in Washington DC – and his team.

Can You Rescue A Rainforest? The Answer May Be Yes:

Half a century after most of Costa Rica’s rainforests were cut down, researchers from the Boyce Thompson Institute took on a project that many thought was impossible – restoring a tropical rainforest ecosystem.

My picks from ScienceDaily

Cooperative Classrooms Lead To Better Friendships, Higher Achievement In Young Adolescents:

Students competing for resources in the classroom while discounting each others’ success are less likely to earn top grades than students who work together toward goals and share their success, according to an analysis of 80 years of research.

Despite Awareness Of Global Warming Americans Concerned More About Local Environment:

British Prime Minister Gordon Brown recently declared climate change a top international threat, and Al Gore urged politicians to get involved to fight global warming. Results from a recent survey conducted by a University of Missouri professor reveal that the U.S. public, while aware of the deteriorating global environment, is concerned predominantly with local and national environmental issues.

Systems Biology Approach Identifies Nutrient Regulation Of Biological Clock In Plants:

Using a systems biological analysis of genome-scale data from the model plant Arabidopsis, an international team of researchers identified that the master gene controlling the biological clock is sensitive to nutrient status. This hypothesis derived from multi-network analysis of Arabidopsis genomic data, and validated experimentally, has shed light on how nutrients affect the molecular networks controlling plant growth and development in response to nutrient sensing.

Weight Bias Is As Prevalent As Racial Discrimination, Study Suggests:

Discrimination against overweight people–particularly women–is as common as racial discrimination, according to a study by the Rudd Center for Food Policy & Obesity at Yale University.

Why Don’t Kids Walk To School Anymore?:

Maybe when we were their age, we walked five miles to school, rain or shine. So why don’t most children today walk or bike to school? It’s not necessarily because they’re spoiled, lazy or over scheduled. According to a University of Michigan researcher, concerns about safety are the main reason that less than 13 percent of U.S. children walked or biked to school in 2004, compared to more than 50 percent who did so in 1969.

My picks from ScienceDaily

Evolution Of New Species Slows Down As Number Of Competitors Increases:

The rate at which new species are formed in a group of closely related animals decreases as the total number of different species in that group goes up, according to new research. The research team believes these findings suggest that new species appear less and less as the number of species in a region approaches the maximum number that it can support.

Zoologists Unlock New Secrets About Frog Deaths:

New research from zoologists at Southern Illinois University Carbondale opens a bigger window to understanding a deadly fungus that is killing off frogs throughout Central and South America, and that could threaten amphibian populations in North America as well.

Heat Stress Model Keeps Cows Cool:

It’s hard to relax if your cattle are stressed, so the ability to predict and avoid potential stressors is essential. Fortunately, an online model developed by scientists with the Agricultural Research Service (ARS) provides information to help cattle–and producers–keep their cool when temperatures rise.

Scientists Learn What’s ‘Up’ With A Class Of Retinal Cells In Mice:

Harvard University researchers have discovered a new type of retinal cell that plays an exclusive and unusual role in mice: detecting upward motion. The cells reflect their function in the physical arrangement of their dendrites, branch-like structures on neuronal cells that form a communicative network with other dendrites and neurons in the brain.

Statistics Are Insufficient For Study Of Proteins’ Signal System: New Study Contradicts Previous Work:

Ten years ago great attention was attracted by the discovery that it was possible to demonstrate signal transfer in proteins using statistical methods. In an article in the journal Proceedings of the National Academy of Science Uppsala researchers are now presenting results of experiments that contradict the theory.

New and Exciting in PLoS Computational Biology

This week’s PLoS Computational Biology is chockful of interesting articles, including these:
Open Access: Taking Full Advantage of the Content:

This Journal and the Public Library of Science (PLoS) at large are standard bearers of the full potential offered through open access publication, but what of you, the reader? For most of you, open access may imply free access to read the journals, but nothing more. There is a far greater potential, but, up to now, little to point to that highlights its tangible benefits. We would argue that, as yet, the full promise of open access has not been realized. There are few persistent applications that collectively use the full on-line corpus, which for the biosciences at least is maintained in PubMed Central (http://www.pubmedcentral.nih.gov/). In short, there are no “killer apps.” Since this readership, beyond any other, would seem to have the ability to change this situation at least in the biosciences, we are issuing a call to action.

Modeling the Effects of Cell Cycle M-phase Transcriptional Inhibition on Circadian Oscillation:

Circadian clock and cell cycle are two important biological processes that are essential for nearly all eukaryotes. The circadian clock governs day and night 24 h periodic molecular processes and physiological behaviors, while cell cycle controls cell division process. It has been widely observed that cell division does not occur randomly across day and night, but instead is normally confined to specific times during day and night. These observations suggest that cell cycle events are gated by the circadian clock. Regarding the biological benefit and rationale for this intriguing gating phenomena, it has been postulated that circadian gating helps to maintain genome stability by confining radiation-sensitive cell cycle phases to night. Bearing in mind the facts that global transcriptional inhibition occurs at cell division and transcriptional inhibition shifts circadian phases and periods, we postulate that confining cell division to specific circadian times benefits the circadian clock by removing or minimizing the side effects of cell division on the circadian clock. Our results based on computational simulation in this study show that periodic transcriptional inhibition can perturb the circadian clock by altering circadian phases and periods, and the magnitude of the perturbation is clearly circadian phase dependent. Specifically, transcriptional inhibition initiated at certain circadian phases induced minimal perturbation to the circadian clock. These results provide support for our postulation. Our postulation and results point to the importance of the effect of cell division on the circadian clock in the interaction between circadian and cell cycle and suggest that it should be considered together with other factors in the exploitation of circadian cell cycle interaction, especially the phenomena of circadian gating of cell cycle.

The Evolution of Robust Development and Homeostasis in Artificial Organisms:

During development, multicellular animals are shaped by cell proliferation, cell rearrangement, and cell death to generate an adult whose form is maintained over time. Disruption of this finely balanced state can have devastating consequences, including aging, psoriasis, and cancer. Typically, however, development is robust, so that animals achieve the same final form even when challenged by environmental damage such as wounding. To see how morphogenetic robustness arises, we have taken an in silico approach to evolve digital organisms that exhibit distinct phases of growth and homeostasis. During the homeostasis period, organisms were found to use a variety of strategies to maintain their form. Remarkably, however, all recovered from severe wounds, despite having evolved in the absence of selection pressure to do so. This ability to regenerate was most striking in an organism with a tissue-like architecture, where it was enhanced by a directional flux of cells that drives tissue turnover. This identifies a stratified architecture, like that seen in human skin and gut, as an evolutionarily accessible and robust form of tissue organisation, and suggests that wound-healing may be a general feature of evolved morphogenetic systems. Both may therefore contribute to homeostasis, wound-healing, and regeneration in real animals.

Shaping Embodied Neural Networks for Adaptive Goal-directed Behavior:

The ability of a brain to learn has been studied at various levels. However, a large gap exists between behavioral studies of learning and memory and studies of cellular plasticity. In particular, much remains unknown about how cellular plasticity scales to affect network population dynamics. In previous studies, we have addressed this by growing mammalian brain cells in culture and creating a long-term, two-way interface between a cultured network and a robot or an artificial animal. Behavior and learning could now be observed in concert with the detailed and long-term electrophysiology. In this work, we used modeling/simulation of living cortical cultures to investigate the network’s capability to learn goal-directed behavior. A biologically inspired simulated network was used to determine an effective closed-loop training algorithm, and the system successfully exhibited multi-task goal-directed adaptive behavior. The results suggest that even though lacking the characteristic layered structure of a brain, the network still could be functionally shaped and showed meaningful behavior. Knowledge gained from working with such closed-loop systems could influence the design of future artificial neural networks, more effective neuroprosthetics, and even the use of living networks themselves as a biologically based control system.

The Dynamics of Human Body Weight Change:

Understanding the dynamics of human body weight change has important consequences for conditions such as obesity, starvation, and wasting syndromes. Changes of body weight are known to result from imbalances between the energy derived from food and the energy expended to maintain life and perform physical work. However, quantifying this relationship has proved difficult, in part because the body is composed of multiple components and weight change results from alterations of body composition (i.e., fat versus lean mass). Here, we show that mathematical modeling can provide a general description of how body weight will change over time by tracking the flux balances of the macronutrients fat, protein, and carbohydrates. For a fixed food intake rate and physical activity level, the body weight and composition will approach steady state. However, the steady state can correspond to a unique body weight or a continuum of body weights that are all consistent with the same food intake and energy expenditure rates. Interestingly, existing experimental data on human body weight dynamics cannot distinguish between these two possibilities. We propose experiments that could resolve this issue and use computer simulations to demonstrate how such experiments could be performed.

My picks from ScienceDaily

Reason For Almost Two Billion Year Delay In Animal Evolution On Earth Discovered:

Scientists from around the world have reconstructed changes in Earth’s ancient ocean chemistry during a broad sweep of geological time, from about 2.5 to 0.5 billion years ago. They have discovered that a deficiency of oxygen and the heavy metal molybdenum in the ancient deep ocean may have delayed the evolution of animal life on Earth for nearly 2 billion years.

Brain’s ‘Sixth Sense’ For Calories Discovered:

The brain can sense the calories in food, independent of the taste mechanism, researchers have found in studies with mice. Their finding that the brain’s reward system is switched on by this “sixth sense” machinery could have implications for understanding the causes of obesity. For example, the findings suggest why high-fructose corn syrup, widely used as a sweetener in foods, might contribute to obesity.

Common Aquatic Animals Show Extreme Resistance To Radiation:

Scientists at Harvard University have found that a common class of freshwater invertebrate animals called bdelloid rotifers are extraordinarily resistant to ionizing radiation, surviving and continuing to reproduce after doses of gamma radiation much greater than that tolerated by any other animal species studied to date.

Mantis Shrimp Vision Reveals New Way That Animals Can See:

Mantis shrimp can see the world in a way that had never been observed in any animal before, researchers report in the March 20th Current Biology, a Cell Press publication. The discovery–which marks the fourth type of visual system–suggests that the ability to perceive circular polarized light may lend mantis shrimp a secret mode of communication.

Elephants Without Borders: Scientists Track African Elephants By Satellite:

In many regions of Africa, elephants are frequent visitors to farms and villages as they roam the landscape searching for food and water. This often brings them into conflict with humans. Researchers at the University of Massachusetts Amherst are tracking their movements through southern and eastern Africa using satellite collars in an effort to understand their ecology and help prevent these conflicts.

My picks from ScienceDaily

Living Upside-down Shapes Spiders For Energy Saving:

An interdisciplinary team of researchers from Spain and Croatia led an investigation into the peculiar lifestyle of numerous spider species, which live, feed, breed and ‘walk’ in an upside-down hanging position. According to their results, such ‘unconventional’ enterprise drives a shape in spiders that confers high energy efficiency, as in oscillatory pendulums.

Space Tourism: Suborbital Vehicle Expected To Fly Within Two Years:

A small California aerospace company has just unveiled a new suborbital spaceship that will provide affordable front-seat rides to the edge of space for the millions of people who want to buy a ticket.

Primitive Mouse-Like Creature May Be Ancestral Mother Of Australia’s Unusual Pouched Mammals:

They are separated by a vast ocean and by millions of years, but tiny prehistoric bones found on an Australian farm have been directly linked to a strange and secretive little animal that lives today in the southern rainforests of South America.

Red Flour Beetle’s Genome Sequenced For The First Time:

An international research consortium with the participation of a research team led by Professor Cornelis Grimmelikhuijzen from the Department of Biology, has sequenced the genome from the red flour beetle Tribolium castaneum. Tribolium is the first beetle and the first insect pest, whose genome has been sequenced. This research may have a big impact on agriculture.

Bear Spray A Viable Alternative To Guns For Deterring Bears, Study Shows:

Hikers and campers venturing into bear country this spring may be safer armed with 8-ounce cans of bear pepper spray than with guns, according to a new study led by a Brigham Young University bear biologist.

My picks from ScienceDaily

Americans Sleeping More, Not Less, Says New Study

Contrary to conventional wisdom, Americans average as much sleep as they did 40 years ago, and possibly more, according to University of Maryland sociologists.

Yes, when you suddenly start including the unemployed in the study.
Mantis Shrimp Vision Reveals New Way That Animals Can See:

Mantis shrimp can see the world in a way that had never been observed in any animal before, researchers report in the March 20th Current Biology, a Cell Press publication. The discovery–which marks the fourth type of visual system–suggests that the ability to perceive circular polarized light may lend mantis shrimp a secret mode of communication.

Ants Are Experienced Fungus Farmers:

It turns out ants, like humans, are true farmers. The difference is that ants are farming fungus.

Delicate Partnership Between Coral And Algae Threatened By Global Warming:

Over two hundred million humans depend for their subsistence on the fact that coral has an addiction to ‘junk food’ – and orders its partners, the symbiotic algae, to make it.

Insects Take A Bigger Bite Out Of Plants In A Higher Carbon Dioxide World:

Atmospheric carbon dioxide levels are rising at an alarming rate, and new research indicates that soybean plant defenses go down as CO2 goes up. Elevated CO2 impairs a key component of the plant’s defenses against leaf-eating insects, according to the report.

New and Exciting in PLoS ONE

Bunch of new, cool stuff in PLoS ONE today – here are the titles that piqued my curiosity (and you know the spiel: rate, note, comment, trackback):
Australia’s Oldest Marsupial Fossils and their Biogeographical Implications:

We describe new cranial and post-cranial marsupial fossils from the early Eocene Tingamarra Local Fauna in Australia and refer them to Djarthia murgonensis, which was previously known only from fragmentary dental remains. The new material indicates that Djarthia is a member of Australidelphia, a pan-Gondwanan clade comprising all extant Australian marsupials together with the South American microbiotheres. Djarthia is therefore the oldest known crown-group marsupial anywhere in the world that is represented by dental, cranial and post-cranial remains, and the oldest known Australian marsupial by 30 million years. It is also the most plesiomorphic known australidelphian, and phylogenetic analyses place it outside all other Australian marsupials. As the most plesiomorphic and oldest unequivocal australidelphian, Djarthia may approximate the ancestral morphotype of the Australian marsupial radiation and suggests that the South American microbiotheres may be the result of back-dispersal from eastern Gondwana, which is the reverse of prevailing hypotheses.

Morphological Evolution of Spiders Predicted by Pendulum Mechanics:

Animals have been hypothesized to benefit from pendulum mechanics during suspensory locomotion, in which the potential energy of gravity is converted into kinetic energy according to the energy-conservation principle. However, no convincing evidence has been found so far. Demonstrating that morphological evolution follows pendulum mechanics is important from a biomechanical point of view because during suspensory locomotion some morphological traits could be decoupled from gravity, thus allowing independent adaptive morphological evolution of these two traits when compared to animals that move standing on their legs; i.e., as inverted pendulums. If the evolution of body shape matches simple pendulum mechanics, animals that move suspending their bodies should evolve relatively longer legs which must confer high moving capabilities. We tested this hypothesis in spiders, a group of diverse terrestrial generalist predators in which suspensory locomotion has been lost and gained a few times independently during their evolutionary history. In spiders that hang upside-down from their webs, their legs have evolved disproportionately longer relative to their body sizes when compared to spiders that move standing on their legs. In addition, we show how disproportionately longer legs allow spiders to run faster during suspensory locomotion and how these same spiders run at a slower speed on the ground (i.e., as inverted pendulums). Finally, when suspensory spiders are induced to run on the ground, there is a clear trend in which larger suspensory spiders tend to run much more slowly than similar-size spiders that normally move as inverted pendulums (i.e., wandering spiders). Several lines of evidence support the hypothesis that spiders have evolved according to the predictions of pendulum mechanics. These findings have potentially important ecological and evolutionary implications since they could partially explain the occurrence of foraging plasticity and dispersal constraints as well as the evolution of sexual size dimorphism and sociality.

Cellular Responses in Sea Fan Corals: Granular Amoebocytes React to Pathogen and Climate Stressors:

Climate warming is causing environmental change making both marine and terrestrial organisms, and even humans, more susceptible to emerging diseases. Coral reefs are among the most impacted ecosystems by climate stress, and immunity of corals, the most ancient of metazoans, is poorly known. Although coral mortality due to infectious diseases and temperature-related stress is on the rise, the immune effector mechanisms that contribute to the resistance of corals to such events remain elusive. In the Caribbean sea fan corals (Anthozoa, Alcyonacea: Gorgoniidae), the cell-based immune defenses are granular acidophilic amoebocytes, which are known to be involved in wound repair and histocompatibility. We demonstrate for the first time in corals that these cells are involved in the organismal response to pathogenic and temperature stress. In sea fans with both naturally occurring infections and experimental inoculations with the fungal pathogen Aspergillus sydowii, an inflammatory response, characterized by a massive increase of amoebocytes, was evident near infections. Melanosomes were detected in amoebocytes adjacent to protective melanin bands in infected sea fans; neither was present in uninfected fans. In naturally infected sea fans a concurrent increase in prophenoloxidase activity was detected in infected tissues with dense amoebocytes. Sea fans sampled in the field during the 2005 Caribbean Bleaching Event (a once-in-hundred-year climate event) responded to heat stress with a systemic increase in amoebocytes and amoebocyte densities were also increased by elevated temperature stress in lab experiments. The observed amoebocyte responses indicate that sea fan corals use cellular defenses to combat fungal infection and temperature stress. The ability to mount an inflammatory response may be a contributing factor that allowed the survival of even infected sea fan corals during a stressful climate event.

Seeing ‘Where’ through the Ears: Effects of Learning-by-Doing and Long-Term Sensory Deprivation on Localization Based on Image-to-Sound Substitution:

Sensory substitution devices for the blind translate inaccessible visual information into a format that intact sensory pathways can process. We here tested image-to-sound conversion-based localization of visual stimuli (LEDs and objects) in 13 blindfolded participants. Subjects were assigned to different roles as a function of two variables: visual deprivation (blindfolded continuously (Bc) for 24 hours per day for 21 days; blindfolded for the tests only (Bt)) and system use (system not used (Sn); system used for tests only (St); system used continuously for 21 days (Sc)). The effect of learning-by-doing was assessed by comparing the performance of eight subjects (BtSt) who only used the mobile substitution device for the tests, to that of three subjects who, in addition, practiced with it for four hours daily in their normal life (BtSc and BcSc); two subjects who did not use the device at all (BtSn and BcSn) allowed assessment of its use in the tasks we employed. The impact of long-term sensory deprivation was investigated by blindfolding three of those participants throughout the three week-long experiment (BcSn, BcSn/c, and BcSc); the other ten subjects were only blindfolded during the tests (BtSn, BtSc, and the eight BtSt subjects). Expectedly, the two subjects who never used the substitution device, while fast in finding the targets, had chance accuracy, whereas subjects who used the device were markedly slower, but showed much better accuracy which improved significantly across our four testing sessions. The three subjects who freely used the device daily as well as during tests were faster and more accurate than those who used it during tests only; however, long-term blindfolding did not notably influence performance. Together, the results demonstrate that the device allowed blindfolded subjects to increasingly know where something was by listening, and indicate that practice in naturalistic conditions effectively improved “visual” localization performance.

Isotope Analysis Reveals Foraging Area Dichotomy for Atlantic Leatherback Turtles:

The leatherback turtle (Dermochelys coriacea) has undergone a dramatic decline over the last 25 years, and this is believed to be primarily the result of mortality associated with fisheries bycatch followed by egg and nesting female harvest. Atlantic leatherback turtles undertake long migrations across ocean basins from subtropical and tropical nesting beaches to productive frontal areas. Migration between two nesting seasons can last 2 or 3 years, a time period termed the remigration interval (RI). Recent satellite transmitter data revealed that Atlantic leatherbacks follow two major dispersion patterns after nesting season, through the North Gulf Stream area or more eastward across the North Equatorial Current. However, information on the whole RI is lacking, precluding the accurate identification of feeding areas where conservation measures may need to be applied. Using stable isotopes as dietary tracers we determined the characteristics of feeding grounds of leatherback females nesting in French Guiana. During migration, 3-year RI females differed from 2-year RI females in their isotope values, implying differences in their choice of feeding habitats (offshore vs. more coastal) and foraging latitude (North Atlantic vs. West African coasts, respectively). Egg-yolk and blood isotope values are correlated in nesting females, indicating that egg analysis is a useful tool for assessing isotope values in these turtles, including adults when not available. Our results complement previous data on turtle movements during the first year following the nesting season, integrating the diet consumed during the year before nesting. We suggest that the French Guiana leatherback population segregates into two distinct isotopic groupings, and highlight the urgent need to determine the feeding habitats of the turtle in the Atlantic in order to protect this species from incidental take by commercial fisheries. Our results also emphasize the use of eggs, a less-invasive sampling material than blood, to assess isotopic data and feeding habits for adult female leatherbacks.

Tool-Use Training in a Species of Rodent: The Emergence of an Optimal Motor Strategy and Functional Understanding:

Tool use is defined as the manipulation of an inanimate object to change the position or form of a separate object. The expansion of cognitive niches and tool-use capabilities probably stimulated each other in hominid evolution. To understand the causes of cognitive expansion in humans, we need to know the behavioral and neural basis of tool use. Although a wide range of animals exhibit tool use in nature, most studies have focused on primates and birds on behavioral or psychological levels and did not directly address questions of which neural modifications contributed to the emergence of tool use. To investigate such questions, an animal model suitable for cellular and molecular manipulations is needed. We demonstrated for the first time that rodents can be trained to use tools. Through a step-by-step training procedure, we trained degus (Octodon degus) to use a rake-like tool with their forelimbs to retrieve otherwise out-of-reach rewards. Eventually, they mastered effective use of the tool, moving it in an elegant trajectory. After the degus were well trained, probe tests that examined whether they showed functional understanding of the tool were performed. Degus did not hesitate to use tools of different size, colors, and shapes, but were reluctant to use the tool with a raised nonfunctional blade. Thus, degus understood the functional and physical properties of the tool after extensive training. Our findings suggest that tool use is not a specific faculty resulting from higher intelligence, but is a specific combination of more general cognitive faculties. Studying the brains and behaviors of trained rodents can provide insights into how higher cognitive functions might be broken down into more general faculties, and also what cellular and molecular mechanisms are involved in the emergence of such cognitive functions.

Regulation of the Neural Circuitry of Emotion by Compassion Meditation: Effects of Meditative Expertise:

Recent brain imaging studies using functional magnetic resonance imaging (fMRI) have implicated insula and anterior cingulate cortices in the empathic response to another’s pain. However, virtually nothing is known about the impact of the voluntary generation of compassion on this network. To investigate these questions we assessed brain activity using fMRI while novice and expert meditation practitioners generated a loving-kindness-compassion meditation state. To probe affective reactivity, we presented emotional and neutral sounds during the meditation and comparison periods. Our main hypothesis was that the concern for others cultivated during this form of meditation enhances affective processing, in particular in response to sounds of distress, and that this response to emotional sounds is modulated by the degree of meditation training. The presentation of the emotional sounds was associated with increased pupil diameter and activation of limbic regions (insula and cingulate cortices) during meditation (versus rest). During meditation, activation in insula was greater during presentation of negative sounds than positive or neutral sounds in expert than it was in novice meditators. The strength of activation in insula was also associated with self-reported intensity of the meditation for both groups. These results support the role of the limbic circuitry in emotion sharing. The comparison between meditation vs. rest states between experts and novices also showed increased activation in amygdala, right temporo-parietal junction (TPJ), and right posterior superior temporal sulcus (pSTS) in response to all sounds, suggesting, greater detection of the emotional sounds, and enhanced mentation in response to emotional human vocalizations for experts than novices during meditation. Together these data indicate that the mental expertise to cultivate positive emotion alters the activation of circuitries previously linked to empathy and theory of mind in response to emotional stimuli.

Genome-Wide Detection of Serpentine Receptor-Like Proteins in Malaria Parasites:

Serpentine receptors comprise a large family of membrane receptors distributed over diverse organisms, such as bacteria, fungi, plants and all metazoans. However, the presence of serpentine receptors in protozoan parasites is largely unknown so far. In the present study we performed a genome-wide search for proteins containing seven transmembrane domains (7-TM) in the human malaria parasite Plasmodium falciparum and identified four serpentine receptor-like proteins. These proteins, denoted PfSR1, PfSR10, PfSR12 and PfSR25, show membrane topologies that resemble those exhibited by members belonging to different families of serpentine receptors. Expression of the pfsrs genes was detected by Real Time PCR in P. falciparum intraerythrocytic stages, indicating that they potentially code for functional proteins. We also found corresponding homologues for the PfSRs in five other Plasmodium species, two primate and three rodent parasites. PfSR10 and 25 are the most conserved receptors among the different species, while PfSR1 and 12 are more divergent. Interestingly, we found that PfSR10 and PfSR12 possess similarity to orphan serpentine receptors of other organisms. The identification of potential parasite membrane receptors raises a new perspective for essential aspects of malaria parasite host cell infection.

My picks from ScienceDaily

New Zealand’s ‘Living Dinosaur’ — The Tuatara — Is Surprisingly The Fastest Evolving Animal:

In a study of New Zealand’s “living dinosaur” the tuatara, evolutionary biologist, and ancient DNA expert, Professor David Lambert and his team from the Allan Wilson Centre for Molecular Ecology and Evolution recovered DNA sequences from the bones of ancient tuatara, which are up to 8000 years old. They found that, although tuatara have remained largely physically unchanged over very long periods of evolution, they are evolving – at a DNA level – faster than any other animal yet examined.

See more….
Computers Show How Bats Classify Plants According To Their Echoes:

Researchers have developed a computer algorithm that can imitate the bat’s ability to classify plants using echolocation. The study represents a collaboration between machine learning scientists and biologists studying bat orientation.

Language Feature Unique To Human Brain Identified:

Researchers at the Yerkes National Primate Research Center, Emory University, have identified a language feature unique to the human brain that is shedding light on how human language evolved. The study marks the first use of diffusion tensor imaging (DTI), a non-invasive imaging technique, to compare human brain structures to those of chimpanzees, our closest living relative.

Unlocking The Psychology Of Snake And Spider Phobias:

University of Queensland researchers have unlocked new evidence that could help them get to the bottom of our most common phobias and their causes. Hundreds of thousands of people count snakes and spiders among their fears, and while scientists have previously assumed we possess an evolutionary predisposition to fear the unpopular animals, researchers at UQ’s School of Psychology may have proved otherwise.

New and Exciting in PLoS Medicine and PLoS Biology

Circadian Remodeling of Neuronal Circuits Involved in Rhythmic Behavior:

Circadian systems evolved as a mechanism that allows organisms to adapt to the environmental changes in light and dark which occur as a consequence of the rotation of Earth. Because of its unique repertoire of genetic tools, Drosophila is a well established model for the study of the circadian clock. Although the biochemical components underlying the molecular oscillations have been characterized in detail, the mechanisms used by the clock neurons to convey information to the downstream pathways remain elusive. In the fruit fly, the small ventral lateral neurons (LNv) are capable of synchronizing other clock cells relying on a neuropeptide named pigment dispersing factor. In this work we introduce a novel mechanism as a possible candidate for contributing to the transmission of information downstream of the small LNvs, involving clock-controlled remodeling of their axonal morphology. By labeling the entire neuronal membrane and analyzing the complexity of the axonal arbor at different times we showed that there is a circadian variation in the complexity of the axonal arbor. This phenomenon was not observed in flies carrying null mutations in two canonical clock genes, underscoring the dependence of the circadian clock for the structural plasticity of its pacemaker neurons.

It’s the Network, Stupid: Why Everything in Medicine Is Connected:

Once the domain of social scientists–who have used social network analysis to study such diverse phenomena as kinship ties, organizational behavior, rumor spreading, and global air traffic–network theory has now entered the purview of health scientists. Network theory is concerned with mapping the links between entities, and social network analysis is the application of that theory to the social sciences. Searching for more social and environmental explanations for the obesity epidemic in America, for example, Christakis and Fowler [1] showed that obesity can spread from person to person, and that this spread depends on the nature of social ties: a person’s chance of becoming obese increased by 171% if he or she had a mutual friend who had become obese (even if they lived far away). Their risk increased by 40% if it was their sibling or spouse who became obese. Christakis and Fowler concluded that the social network is a crucial component–perhaps more so than genetics–in explaining obesity, a problem normally thought of as solely biological and behavioral.

Social Contacts and Mixing Patterns Relevant to the Spread of Infectious Diseases:

Mathematical modelling of infectious diseases transmitted by the respiratory or close-contact route (e.g., pandemic influenza) is increasingly being used to determine the impact of possible interventions. Although mixing patterns are known to be crucial determinants for model outcome, researchers often rely on a priori contact assumptions with little or no empirical basis. We conducted a population-based prospective survey of mixing patterns in eight European countries using a common paper-diary methodology. 7,290 participants recorded characteristics of 97,904 contacts with different individuals during one day, including age, sex, location, duration, frequency, and occurrence of physical contact. We found that mixing patterns and contact characteristics were remarkably similar across different European countries. Contact patterns were highly assortative with age: schoolchildren and young adults in particular tended to mix with people of the same age. Contacts lasting at least one hour or occurring on a daily basis mostly involved physical contact, while short duration and infrequent contacts tended to be nonphysical. Contacts at home, school, or leisure were more likely to be physical than contacts at the workplace or while travelling. Preliminary modelling indicates that 5- to 19-year-olds are expected to suffer the highest incidence during the initial epidemic phase of an emerging infection transmitted through social contacts measured here when the population is completely susceptible. To our knowledge, our study provides the first large-scale quantitative approach to contact patterns relevant for infections transmitted by the respiratory or close-contact route, and the results should lead to improved parameterisation of mathematical models used to design control strategies.

My picks from ScienceDaily

Ancient Lemur’s Little Finger Poses Mystery:

Analysis of the first hand bones belonging to an ancient lemur has revealed a mysterious joint structure that has scientists puzzled.

Impaired Sense Of Smell May Be Early Indicator Of Parkinson’s Disease:

Impaired sense of smell occurs in the earliest stages of Parkinson’s disease (PD) and there is mounting evidence that it may precede motor symptoms by several years, although no large-scale studies had confirmed this. In the first study involving the general population, researchers found that smell impairment can precede the development of PD in men by at least four years.

In Poker, Psychologists Place Bets On Skill:

Is it luck of the draw in poker? No, says Michael DeDonno, a doctoral student from Case Western Reserve University. He suggests putting your bets on skills over luck when playing the card game.

Virtual-reality Video Game To Help Burn Patients Play Their Way To Pain Relief:

To a patient recovering from severe burns, no place would be more soothing than a polar landscape of gently falling snowflakes, snowmen, penguins, igloos and icy rivers. That’s the thinking behind SnowWorld, an interactive, virtual-reality video game being used at Loyola University Hospital in Maywood, Ill., to manage pain felt by burn patients during wound care and physical therapy. Loyola is the first hospital in Illinois and only one of a handful across the nation that is employing this 21st century technology to help burn patients recover from their injuries.

Rwanda Conservation Effort To Link Isolated Chimps To Distant Forest:

A group of some 15 chimpanzees isolated in a pocket of Rwandan rain forest will have a greater range — and, thus, greater chances for survival — thanks to one of Africa’s most ambitious forest restoration and ecological research efforts ever. Organizers of the project, named the Rwandan National Conservation Park, said that a 30-mile (50km) tree corridor will be planted to connect the Gishwati Forest Reserve, the chimpanzees’ home range, to Nyungwe National Park.

My picks from ScienceDaily

Giant Panda Mating Season At National Zoo:

The 2008 giant panda mating season began Tuesday, March 18, at the Smithsonian’s National Zoo. Female Mei Xiang (may-SHONG) and male Tian Tian (tee-YEN tee-YEN) attempted to mate throughout the day Tuesday.

The Song Doesn’t Remain The Same In Fragmented Bird Populations:

The song of passerine birds is a conspicuous and exaggerated display shaped by sexual selection in the context of male-male competition or mate attraction. At the level of the individual, song is considered an indicator of male ‘quality’.

Color Vision System Independent Of Motion Detection in Eye Sight:

The vision system used to process color is separate from that used to detect motion, according to a new study by researchers at New York University’s Center for Developmental Genetics and in the Department of Genetics and Neurobiology at Germany’s University of Würzburg. The findings run counter to previous scholarship that suggested motion detection and color contrast may work in tandem.

Happily Marrieds Have Lower Blood Pressure Than Social Singles:

Happily married adults have lower blood pressure than singles with supportive social networks. Both men and women in happy marriages scored four points lower on 24-hour blood pressure than single adults. Having supportive friends did not translate into improved blood pressure for singles or unhappily marrieds.

Animation Aids Psychology In ‘Second Life’ Experiment:

Bournemouth University’s computer animation experts have been awarded a major grant from the Engineering and Physical Sciences Research Council (EPSRC) to support a three-year project linking animation to psychology.

New and Exciting in PLoS

Plant Classification from Bat-Like Echolocation Signals:

Bats are able to classify plants using echolocation. They emit ultrasonic signals and can recognize the plant according to the echo returning from it. This ability assists them in many of their daily activities, like finding food sources associated with certain plants or using landmarks for navigation or homing. The echoes created by plants are highly complex signals, combining together all the reflections from the many leaves that a plant contains. Classifying plants or other complex objects is therefore considered a troublesome task and we are far from understanding how bats do it. In this work, we suggest a simple algorithm for classifying plants according to their echoes. Our algorithm is able to classify with high accuracy plant echoes created by a sonar head that simulates a typical frequency-modulated bat’s emitting receiving parameters. Our results suggest that plant classification might be easier than formerly considered. It gives us some hints as to which features might be most suitable for the bats, and it opens possibilities for future behavioral experiments to compare its performance with that of the bats.

Evolution of a Core Gene Network for Skeletogenesis in Chordates:

Important molecular mechanisms underlying mammalian skeletogenesis have been described but knowledge about the evolutionary origin of these gene networks is limited. The Runt gene family (Runx1-3) is of extraordinary importance for skeletogenesis. Runx2 deficient mice completely lack bone. Runx2 and Runx3 are essential for cartilage development and Runx2 regulates the key factor Indian hedgehog, which coordinates skeletogenesis. Here, we reconstructed Runt gene evolution in correlation to skeletal evolution. By analyzing lancelets, one of the closest living relatives of vertebrates, we revealed that the single Runt and Hedgehog family founder genes were co-expressed in primitive skeletal elements of the chordate stem species. Interestingly, at this stage the Runt and Hedgehog pathways were already directly linked to one another. Furthermore we isolated two Runt genes from a representative of jawless cartilaginous fish (hagfish) and three Runt genes from jawed cartilaginous fish (dogfish) which were all expressed in cartilage. The dogfish Runt genes were also found in teeth and placoid scales. This study suggests that Runt genes were involved in all ancient processes of chordate skeletogenesis. Furthermore the analysis supports the theory that most likely the gut was the tissue that originally secreted an acellular gill gut skeleton in the chordate ancestor.

My picks from ScienceDaily

What Gets A Female’s Attention, At Least A Songbird’s:

Male songbirds produce a subtly different tune when they are courting a female than when they are singing on their own. Now, new research offers a window into the effect this has on females, showing they have an ear for detail. The finding provides insights not only into the intricacies of songbird attraction and devotion but also into the way in which the brain develops and responds to social cues, in birds — and humans.

Oldest Cretaceous Period Dinosaur Discovered Represents New Genus Of Prehistoric Aquatic Predator:

One of the oldest and most complete plesiosaur fossils recovered in North America, and the oldest yet discovered from the Cretaceous Period, represents a new genus of the prehistoric aquatic predator according to University of Calgary palaeontologists who have formally described the creature after its remains were uncovered in a Syncrude Canada Ltd. mine near Fort McMurray in 1994.

Skulls Of Modern Humans And Ancient Neanderthals Evolved Differently Because Of Chance, Not Natural Selection:

New research led by UC Davis anthropologist Tim Weaver adds to the evidence that chance, rather than natural selection, best explains why the skulls of modern humans and ancient Neanderthals evolved differently. The findings may alter how anthropologists think about human evolution.

Rethinking Early Evolution: Earth’s Earliest Animal Ecosystem Was Complex And Included Sexual Reproduction:

Two paleontologists studying ancient fossils they excavated in the South Australian outback argue that Earth’s ecosystem has been complex for hundreds of millions of years — at least since around 565 million years ago, which is included in a period in Earth’s history called the Neoproterozoic era.

Men And Women Have Different Eating Habits, Study Shows:

When it comes to what we eat, men and women really are different according to scientific research presented today (March 19) at the 2008 International Conference on Emerging Infectious Diseases in Atlanta, Georgia. In general, men are more likely to report eating meat and poultry items and women are more likely to report eating fruits and vegetables.

Cause Of Death Of Russian Baby Mammoth Discovered:

On September 27, 2004, the front part of a baby mammoth’s body was found in Olchan mine in the Oimyakon Region of Yakutia. Specialists of the Museum of Mammoth of the Institute of Applied Ecology of the North, Academy of Sciences of Sakha Republic (Yakutia), have been thoroughly studying the finding and they have published the first outcomes.

Unlocking The Psychology Of Snake And Spider Phobias:

University of Queensland researchers have unlocked new evidence that could help them get to the bottom of our most common phobias and their causes.

My picks from ScienceDaily

Loss Of Egg Yolk Genes In Mammals And The Origin Of Lactation And Placentation:

If you are reading this, you did not start your life by hatching from an egg. This is one of the many traits that you share with our mammalian relatives. A new article explores the genetic changes that led mammals to feed their young via the placenta and with milk, rather then via the egg, and finds that these changes occurred fairly gradually in our evolutionary history. The paper shows that milk-protein genes arose in a common ancestor of all existing mammalian lineages and preceded the loss of the genes that encoded egg proteins.

Saving Spanish Brown Bears With Help From European Bears Might Make Sense:

Brown bears from the Iberian Peninsula are not as genetically different from other brown bears in Europe as was previously thought. An international study being published in Proceedings of the National Academy of Sciences, shows that, to the contrary, the Spanish bear was only recently isolated from other European strains. These findings shed new light on the discussion of how to save the population of Spanish bears.

Like Sweets? You’re More Like A Fruit Fly Than You Think:

According to researchers at the Monell Center, fruit flies are more like humans in their responses to many sweet tastes than are almost any other species.

Royal Jelly Makes Bee Queens, Boosts Nurture Case:

New ANU research may explain why eating royal jelly destines honeybee larvae to become queens instead of workers – and in the process adds new weight to the role of environmental factors in the nature/nurture divide.

Asia’s Odd-ball Antelope Faces Migration Crisis:

Take a deer’s body, attach a camel’s head and add a Jimmy Durante nose, and you have a saiga — the odd-ball antelope with the enormous schnoz that lives on the isolated steppes of Central Asia. Unfortunately, they are as endangered as they are strange-looking due to over-hunting. Now, according to a recent Wildlife Conservation Society study, their migration routes are in jeopardy as well.

See also.

New and Exciting in PLoS ONE

There are 41 new articles published in PLoS ONE tonight. Look around, rate, comment, and send trackbacks. Here are my picks for this week:

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My picks from ScienceDaily

Hissing Cockroaches Are Popular, But They Also Host Potent Mold Allergens:

Their gentle nature, large size, odd sounds and low-maintenance care have made Madagascar hissing cockroaches popular educational tools and pets for years. But the giant insects also have one unfortunate characteristic: Their hard bodies and feces are home to many mold species that could be triggering allergies in the kids and adults who handle the bugs, according to a new study.

Tiny Wasp Used To Wipe Out Major Agricultural Pest In Tahiti:

A research team led by Mark Hoddle, a biological control specialist at UC Riverside, has nearly eradicated the glassy-winged sharpshooter, a major agricultural pest, from the island of Tahiti and several other French Polynesian islands in the South Pacific Ocean. To achieve total pest suppression, the researchers used biological control, an inexpensive method that provides permanent control and can be applied to areas where the sharpshooter has become a nuisance.

Turtle Nesting Threatened By Logging Practices In Gabon, Smithsonian Warns:

Endangered sea turtles are victims of sloppy logging practices in the west central African country Gabon, according to a study led by William Laurance, staff scientist at the Smithsonian Tropical Research Institute.

Heart-healthy Yak Cheese:

In a finding likely to get cheese lovers talking, researchers in Nepal and Canada report that yak cheese contains higher levels of heart-healthy fats than cheese from dairy cattle, and may be healthier.

Clovis-age Overkill Didn’t Take Out California’s Flightless Sea Duck:

Clovis-age natives, often noted for overhunting during their brief dominance in a primitive North America, deserve clemency in the case of California’s flightless sea duck. New evidence says it took thousands of years for the duck to die out.

First ‘Rule’ Of Evolution Suggests That Life Is Destined To Become More Complex:

Researchers have found evidence which suggests that evolution drives animals to become increasingly more complex.

Gecko’s ‘Active’ Tail Key To Preventing Falls And Aerial Maneuvers:

How useful is an animal’s tail? For the gecko, unlike most animals, it could be a matter of life or death, according to new research from the University of California, Berkeley.

Time Isn’t Money: Study Finds That We Spend The Resources Differently:

Economists usually treat time like money — as another scarce resource that people spend to achieve certain ends. Money is used to pay for things like furniture and plane tickets; time is spent assembling the do-it-yourself bookshelf or searching for cheap flights on the Internet. But despite the old adage that time is money, the two are far from psychologically equivalent, reveals a new study — particularly when it comes to consumer spending decisions.

Does Touch Affect Flavor? Study Finds That How A Container Feels Can Affect Taste:

Does coffee in a flimsy cup taste worse than coffee in a more substantial cup? Firms such as McDonalds and Starbucks spend millions of dollars every year on disposable packaging, but a new study suggests that trying to skimp in this area might not be worth it — and may negatively impact consumers’ perceptions of taste and quality.

New and Exciting in PLoS Biology

Loss of Egg Yolk Genes in Mammals and the Origin of Lactation and Placentation:

Egg yolk contains the nutrients required for the development of the nonmammalian vertebrate embryo. These nutrients derive by and large from a single set of proteins, vitellogenins, which are produced in the liver and provide or transport amino acids, lipids, phosphorous, and calcium to the egg. Mammals have evolved new nutritional resources for their developing and early offspring, such as lactation and placentation. However, the evolutionary timing and molecular events associated with this major phenotypic transition are not well understood. In this study, we have investigated the evolutionary fate of the three ancestral vitellogenin-encoding genes in mammals. Using detailed evolutionary analyses of genomes from the three major mammalian lineages (eutherian “placental” mammals, marsupials, and monotremes), we found that these genes progressively lost their functions and became pseudogenes relatively recently during mammalian evolution (the most recent inactivation event occurred roughly 30-70 million years ago). Monotremes, which lactate yet lay small parchment-shelled eggs, even retained a functional vitellogenin gene, consistent with their intermediate reproductive state. Our analyses also provide evidence that the major milk resource genes, caseins, which have similar functional properties as vitellogenins, appeared in the common mammalian ancestor ∼200-310 million years ago. Based on our data, we suggest that the emergence of the alternative resources for the mammalian young–lactation and then placentation–only gradually reduced the need for egg yolk resources (and hence functional vitellogenin genes) in mammals.

See also the synopsis, For Mammals, Loss of Yolk and Gain of Milk Went Hand in Hand, and blog posts, Got Milk? Lactation and Placentation Replace Yolky Eggs, Got yolk?, Which came first, the mammalian breast or the placenta? and Reproductive history writ in the genome
Change the IUCN Protected Area Categories to Reflect Biodiversity Outcomes:

In 1872, United States President Ulysses Grant set aside 2.2 million acres of wilderness, primarily for recreational purposes, as the first formally recognized protected area (PA)–Yellowstone National Park. The concept took hold slowly over the next hundred years, and PAs are now recognized as essential to biodiversity conservation [1] and as irreplaceable tools for species and habitat management and recovery. Today, over 100,000 sites (11.5% of the Earth’s land surface) are listed in the World Database on Protected Areas [2]. PAs have always been recognized as having broad roles, but it wasn’t until the 1990s that the International Union for the Conservation of Nature (IUCN) included the role of conserving biodiversity in its definition: “An area of land and/or sea especially dedicated to the protection and maintenance of biological diversity, and of natural and associated cultural resources, and managed through legal or other effective means” [3].

See also this blog post: Issues for the IUCN: Redefining Protected Areas
Social Context-Induced Song Variation Affects Female Behavior and Gene Expression:

Vocal communication in many species, including humans, is affected by social cues. In the zebra finch, for example, males make subtle changes to the length, tempo, and variability of their courtship songs (directed songs) relative to songs performed in isolation (undirected songs). Using a behavioral approach assay, we found that female zebra finches strongly prefer the sound of directed over undirected song. Interestingly, female preferences were influenced by the variability of note pitch, showing stronger preferences for directed songs when they were less variable in pitch than the undirected songs. Pitch variability is controlled by a forebrain-basal ganglia circuit, which may represent a neural substrate on which selection acts to shape behavior. Preference for directed song was also increased when the singer was familiar to the listener, suggesting that song preferences are enhanced by experience. Based on the expression of an immediate early gene associated with memory formation and plasticity, we found that two high-level auditory areas were differentially responsive to the category of song females heard, with one area responding to whether songs were directed or undirected, and a second area to whether songs were familiar or unfamiliar. Together, these data demonstrate that females detect and prefer the male’s changed performance during courtship singing and suggest that neurons in high-level auditory areas are involved in this social perception.

My picks from ScienceDaily

New Bird Species Discovered:

The announcement of the discovery of a new bird comes with a twist: It’s a white-eye, but its eye isn’t white. Still, what this new bird lacks in literal qualities it makes up for as one of the surprises that nature still has tucked away in little-explored corners of the world.

Flexible Mating Calls May Contribute To Ecological Success Of Species:

Katydid (or didn’t she?) respond to the mating call of her suitors. According to scientists at the University of Missouri, one species of katydid may owe its ecological success and expanded habitat range to the ability of male katydids to adjust their mating calls to attract females.

Rare North Island Brown Kiwi Hatches At Smithsonian’s National Zoo:

Early Friday morning, March 7, one of the world’s most endangered species–a North Island brown kiwi–hatched at the Smithsonian’s National Zoo Bird House. Keepers had been incubating the egg for five weeks, following a month long incubation by the chick’s father, carefully monitoring it for signs of pipping: the process in which the chick starts to break through the shell. The chick remained in an isolet for four days and is now in a specially designed brooding box.

Like Dogs, Like Humans? Day Blindness In The Wirehaired Dachshund:

For his Ph. D. degree, Ernst-Otto Ropstad investigated the retinal disease called cone-rod dystrophy in the Norwegian population of wirehaired dachshunds. His findings are of comparative interest for the corresponding disease in people.

My picks from ScienceDaily

Early Bird Doesn’t Always Get The Worm:

Competing against older brothers and sisters can be tough work, as any youngest child will tell you. But new research from a biologist at the University of North Carolina at Chapel Hill shows that when it comes to some birds, you should reserve any underdog sympathies for the first born — or rather, first laid — siblings as well.

Many Teens Spend 30 Hours A Week On ‘Screen Time’ During High School:

While most teenagers (60 percent) spend on average 20 hours per week in front of television and computer screens, a third spend closer to 40 hours per week, and about 7 percent are exposed to more than 50 hours of ‘screen-time’ per week, according to a study presented at the American Heart Association’s 48th Annual Conference on Cardiovascular Disease Epidemiology and Prevention.

Bird Brains Suggest How Vocal Learning Evolved:

Though they perch far apart on the avian family tree, birds with the ability to learn songs use similar brain structures to sing their tunes. Neurobiologists at Duke University Medical Center now have an explanation for this puzzling likeness.

Correct Levels Of Stress Hormones Boost Learning, Squirrel Study Suggests:

Tests on the influence that a stress-related hormone has on learning in ground squirrels could have an impact on understanding how it influences human learning, according to a University of Chicago researcher.

Bipolar Disorder: Manic Mouse Made With One Gene Missing:

Bipolar Disorder (BPD or manic-depressive illness) is one of the most serious of all mental disorders, affecting millions of individuals worldwide. Affected individuals alternate between states of deep depression and mania. While depression is characterized by persistent and long-term sadness or despair, mania is a mental state characterized by great excitement, flight of ideas, a decreased need for sleep, and, sometimes, uncontrollable behavior, hallucinations, or delusions. BPD likely arises from the complex interaction of multiple genes and environmental factors. Unlike some brain diseases, no single gene has been implicated in BPD.

Adolescent Girls With ADHD Are At Increased Risk For Eating Disorders, Study Shows:

Girls with attention deficit hyperactivity disorder stand a substantially greater risk of developing eating disorders in adolescence than girls without ADHD, a new study has found.

Emotional ‘Bummer’ Of Cocaine Addiction Mimicked In Animals:

Cocaine addicts often suffer a downward emotional spiral that is a key to their craving and chronic relapse. While researchers have developed animal models of the reward of cocaine, they have not been able to model this emotional impact, until now. Regina Carelli and colleagues report experiments with rats in which they have mimicked the negative affect of cocaine addiction and even how it drives greater cocaine use. They said their animal model could enable better understanding of the emotional motivations of cocaine addiction and how to ameliorate them.

How Social Pressure Increases Voter Turnout: Evidence From A Large-scale Field Experiment:

New research by political scientists concludes that direct mail campaigns which include a social pressure aspect are more effective at increasing voter turnout and are cheaper than other forms of voter mobilization, including door-to-door or telephone canvassing.

My picks from ScienceDaily

Bird Brains Suggest How Vocal Learning Evolved:

Though they perch far apart on the avian family tree, birds with the ability to learn songs use similar brain structures to sing their tunes. Neurobiologists at Duke University Medical Center now have an explanation for this puzzling likeness.

Alligators’ Muscles Move Lungs Around For Sneaky Maneuvers In Water:

Without a ripple in the water, alligators dive, surface or roll sideways, even though they lack flippers or fins. University of Utah biologists discovered gators maneuver silently by using their diaphragm, pelvic, abdominal and rib muscles to shift their lungs like internal floatation devices: toward the tail when they dive, toward the head when they surface and sideways when they roll.

Amphibians Respond Behaviorally To Impact Of Clear Cutting:

The number of amphibians drastically decreases in forest areas that are clearcut, according to previous studies. A University of Missouri researcher, however, has found that some animals may not be dying. Instead, the Mizzou biologist said some animals may be moving away (possibly to return later) or retreating underground. The finding could have major implications for both the timber industry and the survival of amphibians.

Chemicals Like DEET In Bug Spray Work By Masking Human Odors:

Fifty years have passed since the United States Department of Agriculture and the U.S. Army invented DEET to protect soldiers from disease-transmitting insects (and, in the process, made camping trips and barbecues more pleasant for the rest of us civilians). But despite decades of research, scientists still didn’t know precisely how it worked. Now, by pinpointing DEET’s molecular target in insects, researchers at Rockefeller University have definitively shown that the widely used bug repellent acts like a chemical cloak, masking human odors that blood-feeding insects find attractive.

Royal Corruption Is Rife In The Ant World:

Far from being a model of social co-operation, the ant world is riddled with cheating and corruption — and it goes all the way to the top, according to scientists from the Universities of Leeds and Copenhagen.

Majestic Lesser Flamingos Survive In Contaminated Indian Waters:

A University of Leicester ecologist is setting out to discover why flamingos are so in the pink of health – in the poo!

My picks from ScienceDaily

Snakes Vault Past Toxic Newts In Evolutionary Arms Race:

Snakes don’t eat fugu, the seafood delicacy prepared from blowfish meat and famed for its poisonous potential. However, should a common garter snake wander into a sushi restaurant, it could fearlessly order a fugu dinner.

Bipolar Disorder: Manic Mouse Made With One Gene Missing:

Bipolar Disorder (BPD or manic-depressive illness) is one of the most serious of all mental disorders, affecting millions of individuals worldwide. Affected individuals alternate between states of deep depression and mania. While depression is characterized by persistent and long-term sadness or despair, mania is a mental state characterized by great excitement, flight of ideas, a decreased need for sleep, and, sometimes, uncontrollable behavior, hallucinations, or delusions. BPD likely arises from the complex interaction of multiple genes and environmental factors. Unlike some brain diseases, no single gene has been implicated in BPD.

Domestication Of The Donkey May Have Taken A Long Time:

An international group of researchers has found evidence for the earliest transport use of the donkey and the early phases of donkey domestication, suggesting the process of domestication may have been slower and less linear than previously thought.

Cooperation Between Figs, Wasps And Parasites Proves Three Is Not Always A Crowd:

Scientists Simon Segar, James Cook, Derek Dunn, and colleagues at the University of Reading have found that during mutualism, a cooperative relationship between two different species, a third parasitic species may help to keep the relationship stable. During mutualism, both species benefit. However, the long-term relationship between them can be threatened by individuals who take too much advantage of the relationship in the short-term for their own benefit.

More
Sand Dollar Larvae Use Cloning To ‘Make Change,’ Confound Predators:

Nature is full of examples of creatures that try to look as big as possible in an effort to scare away potential predators. But to avoid being eaten alive the larvae of sand dollars appear to have a different strategy, in a way exchanging a dollar for a couple of dimes.

More….
Dynamic Visualization Made Of Simplest Circadian Clock:

Scientists have acquired a more dynamic picture of events that underlie the functions of a bacterial biological clock. New research shows how the simplest organism known to have a circadian clock keeps time and may enhance our understanding of how other organisms establish and govern chronological rhythms.

My picks from ScienceDaily

Insect’s Sensory Data Tells A New Story About Neural Networks:

A group of researchers has developed a novel way to view the world through the eyes of a common fly and partially decode the insect’s reactions to changes in the world around it. The research fundamentally alters earlier beliefs about how neural networks function and could provide the basis for intelligent computers that mimic biological processes.

One In Four Teenage Girls In U.S. Has Sexually Transmitted Disease, CDC Study Shows:

A new CDC study estimates that one in four (26 percent) young women between the ages of 14 and 19 in the United States – or 3.2 million teenage girls – is infected with at least one of the most common sexually transmitted diseases (human papillomavirus (HPV), chlamydia, herpes simplex virus, and trichomoniasis). The study, presented today at the 2008 National STD Prevention Conference, is the first to examine the combined national prevalence of common STDs among adolescent women in the United States, and provides the clearest picture to date of the overall STD burden in adolescent women.

Climate Change Predicted To Have Major Impact On Transportation Infrastructure And Operations:

While every mode of transportation in the U.S. will be affected as the climate changes, potentially the greatest impact on transportation systems will be flooding of roads, railways, transit systems, and airport runways in coastal areas because of rising sea levels and surges brought on by more intense storms, says a new report from the National Research Council. Though the impacts of climate change will vary by region, it is certain they will be widespread and costly in human and economic terms, and will require significant changes in the planning, design, construction, operation, and maintenance of transportation systems.

Startling Discovery About Photosynthesis: Many Marine Microorganism Skip Carbon Dioxide And Oxygen Step:

A startling discovery by scientists at the Carnegie Institution puts a new twist on photosynthesis, arguably the most important biological process on Earth. Photosynthesis by plants, algae, and some bacteria supports nearly all living things by producing food from sunlight, and in the process these organisms release oxygen and absorb carbon dioxide. But two studies by Arthur Grossman and colleagues*+ reported in Biochimica et Biophysica Acta and Limnology and Oceanography suggest that certain marine microorganisms have evolved a way to break the rules–they get a significant proportion of their energy without a net release of oxygen or uptake of carbon dioxide. This discovery impacts not only scientists’ basic understanding of photosynthesis, but importantly, it may also impact how microorganisms in the oceans affect rising levels of atmospheric carbon dioxide.

Evidence Of Ice Age Hunters: 28 Palaeolithic Handaxes Found In North Sea:

An amazing haul of 28 flint hand-axes, dated by archaeologists to be around 100,000 years-old, have been unearthed in gravel from a licensed marine aggregate dredging area 13km off Great Yarmouth.

Sperm-Check Home Test Receives FDA Approval:

Technology developed at the University of Virginia could soon have a dramatic impact on male contraception practices throughout the U.S. Earlier this year, the U.S. Food and Drug Administration approved SpermCheck Vasectomy, a home test that confirms men’s post-vasectomy sterility and is based on discoveries made at U.Va.

Which Came First, Social Dominance Or Big Brains? Wasps May Tell:

There’s new evidence supporting the idea that bigger brains are better. A study of a tropical wasp suggests that the brainpower required to be dominant drives brain capacity.

New and Exciting in PLoS ONE

There are 48 new articles published in PLoS ONE this week. Rate, comment, send trackbacks….
The Phylogeny of the Four Pan-American MtDNA Haplogroups: Implications for Evolutionary and Disease Studies:

Only a limited number of complete mitochondrial genome sequences belonging to Native American haplogroups were available until recently, which left America as the continent with the least amount of information about sequence variation of entire mitochondrial DNAs. In this study, a comprehensive overview of all available complete mitochondrial DNA (mtDNA) genomes of the four pan-American haplogroups A2, B2, C1, and D1 is provided by revising the information scattered throughout GenBank and the literature, and adding 14 novel mtDNA sequences. The phylogenies of haplogroups A2, B2, C1, and D1 reveal a large number of sub-haplogroups but suggest that the ancestral Beringian population(s) contributed only six (successful) founder haplotypes to these haplogroups. The derived clades are overall starlike with coalescence times ranging from 18,000 to 21,000 years (with one exception) using the conventional calibration. The average of about 19,000 years somewhat contrasts with the corresponding lower age of about 13,500 years that was recently proposed by employing a different calibration and estimation approach. Our estimate indicates a human entry and spread of the pan-American haplogroups into the Americas right after the peak of the Last Glacial Maximum and comfortably agrees with the undisputed ages of the earliest Paleoindians in South America. In addition, the phylogenetic approach also indicates that the pathogenic status proposed for various mtDNA mutations, which actually define branches of Native American haplogroups, was based on insufficient grounds.

Laterality and Flight: Concurrent Tests of Side-Bias and Optimality in Flying Tree Swallows:

Behavioural side-bias occurs in many vertebrates, including birds as a result of hemispheric specialization and can be advantageous by improving response times to sudden stimuli and efficiency in multi-tasking. However, behavioural side-bias can lead to morphological asymmetries resulting in reduced performance for specific activities. For flying animals, wing asymmetry is particularly costly and it is unclear if behavioural side-biases will be expressed in flight; the benefits of quick response time afforded by side-biases must be balanced against the costs of less efficient flight due to the morphological asymmetry side-biases may incur. Thus, competing constraints could lead to context-dependent expression or suppression of side-bias in flight. In repeated flight trials through an outdoor tunnel with obstacles, tree swallows (Tachycineta bicolor) preferred larger openings, but we did not detect either individual or population-level side-biases. Thus, while observed behavioural side-biases during substrate-foraging and copulation are common in birds, we did not see such side-bias expressed in obstacle avoidance behaviour in flight. This finding highlights the importance of behavioural context for investigations of side-bias and hemispheric laterality and suggests both proximate and ultimate trade-offs between species-specific cognitive ecology and flight biomechanics.

Molecular Mapping of Movement-Associated Areas in the Avian Brain: A Motor Theory for Vocal Learning Origin:

Vocal learning is a critical behavioral substrate for spoken human language. It is a rare trait found in three distantly related groups of birds-songbirds, hummingbirds, and parrots. These avian groups have remarkably similar systems of cerebral vocal nuclei for the control of learned vocalizations that are not found in their more closely related vocal non-learning relatives. These findings led to the hypothesis that brain pathways for vocal learning in different groups evolved independently from a common ancestor but under pre-existing constraints. Here, we suggest one constraint, a pre-existing system for movement control. Using behavioral molecular mapping, we discovered that in songbirds, parrots, and hummingbirds, all cerebral vocal learning nuclei are adjacent to discrete brain areas active during limb and body movements. Similar to the relationships between vocal nuclei activation and singing, activation in the adjacent areas correlated with the amount of movement performed and was independent of auditory and visual input. These same movement-associated brain areas were also present in female songbirds that do not learn vocalizations and have atrophied cerebral vocal nuclei, and in ring doves that are vocal non-learners and do not have cerebral vocal nuclei. A compilation of previous neural tracing experiments in songbirds suggests that the movement-associated areas are connected in a network that is in parallel with the adjacent vocal learning system. This study is the first global mapping that we are aware for movement-associated areas of the avian cerebrum and it indicates that brain systems that control vocal learning in distantly related birds are directly adjacent to brain systems involved in movement control. Based upon these findings, we propose a motor theory for the origin of vocal learning, this being that the brain areas specialized for vocal learning in vocal learners evolved as a specialization of a pre-existing motor pathway that controls movement.

Ovulation Order Mediates a Trade-Off between Pre-Hatching and Post-Hatching Viability in an Altricial Bird:

Simultaneously dependent siblings often compete for parentally provided resources. This competition may lead to mortality, the probability of which may be a function, in part, of the individual offspring’s production order. In birds, serial ovulation followed by hatching asynchrony of simultaneous dependents leads to differences in post-hatching survival that largely depend on ovulation (laying) order. This has led to the widespread assumption that early-laid eggs are of greater value and therefore should possess different maternally manipulated characteristics than later-laid eggs. However, this perspective ignores the potential effect of laying order on pre-hatching viability, an effect which some studies suggest should offset the effect of laying order on post-hatching viability. I examined the relationship between laying order and hatching and fledging probability in wild, free-living Lincoln’s sparrows (Melospiza lincolnii). In broods with complete hatching success, first-laid and therefore first-hatched offspring had the highest probability of fledging, and fledging probability declined with increasing laying order. However, first-laid eggs were less likely than later-laid eggs to hatch. This effect of laying order on pre-hatching viability seemed to offset that on post-hatching viability, and, consistently, maternal investment in egg size varied little if at all with respect to laying order. These results suggest that ovulation order mediates a trade-off between pre-hatching and post-hatching viability and should encourage a re-evaluation of the solitary role post-embryonic survival often plays when researchers make assumptions about the value of propagules based on the order in which they are produced.

My picks from ScienceDaily

Micronesian Islands Colonized By Small-bodied Humans:

Since the reporting of the so-called “hobbit” fossil from the island of Flores in Indonesia, debate has raged as to whether these remains are of modern humans (Homo sapiens), reduced, for some reason, in stature, or whether they represent a new species, Homo floresiensis. Lee Berger and colleagues from the University of the Witwatersrand, Rutgers University and Duke University, describe the fossils of small-bodied humans from the Micronesian island of Palau. These people inhabited the island between 1400 and 3000 years ago and share some — although not all — features with the H. floresiensis specimens.

See more here, here, here and here.
Fossilized Giant Rhino Bone Questions Isolation Of Anatolia, 25 Million Years Ago:

Contrary to generally accepted belief, Anatolia1 was not geographically isolated 25 million years ago (during the Oligocene epoch): this has just been demonstrated by researchers from the Laboratoire des Mécanismes et Transferts en Géologie (LMTG) (CNRS/ University of Toulouse 3/IRD) and the Paléobiodiversité et paléoenvironnements laboratory (CNRS/Muséum national d’histoire naturelle/University of Paris 6).

How Frequency Of Meals May Affect Health:

The health consequences of eating one large meal a day compared with eating three meals a day has not been established. Now two recently published journal articles are among the first to report the effects of meal skipping on key health outcomes, based on a study involving a group of normal-weight, middle-aged adults.

Invasive Species Can Produce ‘Hotspots Of Evolutionary Novelty,’ Study Shows:

When exotic species invade new territory, they often present a major threat to the other plants and animals living there–that much is clear. But researchers writing in the March 11th issue of Current Biology now show that, in addition to their destructive tendencies, invasive species can also have a surprisingly “creative” side.

Non-human Primates Convey Meaning Through Call Combinations:

Researchers have made what they say is the first experimental demonstration that a primate other than humans conveys meaning by combining distinct alarm calls in particular ways.

Mystery Behind The Strongest Creature In The World:

The strongest creature in the world, the Hercules Beetle, has a colour-changing trick that scientists have long sought to understand. New research details an investigation into the structure of the specie’s peculiar protective shell which could aid design of ‘intelligent materials’.

Wandering Albatrosses Follow Their Nose:

The first study of how individual wandering albatrosses find food shows that the birds rely heavily on their sense of smell. The birds can pick up a scent from several miles away, U.S. and French researchers have found.

New and Exciting in PLoS

Lots of interesting stuff in PLoS Medicine and PLoS Biology this week, as well as a special, one-day-in-advance paper in PLoS ONE:
Small-Bodied Humans from Palau, Micronesia:

Newly discovered fossil assemblages of small bodied Homo sapiens from Palau, Micronesia possess characters thought to be taxonomically primitive for the genus Homo. Recent surface collection and test excavation in limestone caves in the rock islands of Palau, Micronesia, has produced a sizeable sample of human skeletal remains dating roughly between 940-2890 cal ybp. Preliminary analysis indicates that this material is important for two reasons. First, individuals from the older time horizons are small in body size even relative to “pygmoid” populations from Southeast Asia and Indonesia, and thus may represent a marked case of human insular dwarfism. Second, while possessing a number of derived features that align them with Homo sapiens, the human remains from Palau also exhibit several skeletal traits that are considered to be primitive for the genus Homo. These features may be previously unrecognized developmental correlates of small body size and, if so, they may have important implications for interpreting the taxonomic affinities of fossil specimens of Homo.

Predators Make (Temporary) Escape from Coevolutionary Arms Race:

Arguably cute and spanning at most 20 cm from head to tail, the rough-skinned newt packs pretty near the most poisonous punch known to the animal kingdom. Taricha granulosa, like all species in its genus, exudes an exceptionally potent neurotoxin, tetrodotoxin (TTX) from its skin glands. Some Taricha newts could wipe out thousands of mice or a clutch of humans with their toxic issue. But why produce enough poison to kill a potential predator several times over? To discourage the one predator–the common garter snake (Thamnophis sirtalis)–that’s resistant enough to the poison to count on newts as a food source.

Phenotypic Mismatches Reveal Escape from Arms-Race Coevolution:

Arms races between natural enemies can lead to the rapid evolution of extreme traits, high degrees of specialization, and the formation of new species. They also serve as the ecological model for the evolution of drug resistance by diseases and for host-pathogen interactions in general. Revealing who wins these arms races and how they do so is critical to our understanding of these processes. Capitalizing on the geographic mosaic of species interactions, we examined the dynamics of the arms race between snakes and their toxic newt prey. Garter snakes in some populations have evolved dramatic resistance to the tetrodotoxin defense of the their local prey. By evaluating the pattern of mismatches between toxicity and resistance, we discovered that predators sometimes escape the arms race through the evolution of extreme resistance, but that prey never come out ahead. The reason for this one-sided outcome appears to depend on the molecular genetic basis of resistance in snakes, wherein changes to a single amino acid residue can confer huge differences in resistance.

A Role for Parasites in Stabilising the Fig-Pollinator Mutualism:

Much biodiversity ultimately relies on cooperation between different species, interactions called mutualisms. Benefits to one partner are gained by obtaining resources from the other, presenting a problem: what prevents one partner from exploiting the other at an unsustainable level? Fig trees are pollinated by tiny wasps that only develop successfully themselves by each destroying a single female fig flower that would otherwise become a seed. Wasps tend to occur in long flowers near the fruit’s centre, with seeds developing near the outer wall. Female wasps therefore favour long flowers for their offspring, and leave short flowers to develop into seeds. To understand why wasps exploit fig trees sustainably, we need to explain why this preference has evolved. The fig-pollinator mutualism is exploited by small parasitic wasps that attack pollinators from outside the fruit. In three Australasian fig species, we found that pollinator offspring in the outer layer of flowers were more likely to be parasitized than those in the inner layer. Our data thus indicate that long flowers provide enemy-free space for pollinator offspring at the fruit’s centre. We suggest that the provision of variable length flowers by fig trees may contribute to mutualism stability by indirectly involving a third party: parasitic wasps, previously regarded as detrimental to both mutualists.

Observational Research, Randomised Trials, and Two Views of Medical Science:

Two views exist of medical science: one emphasises discovery and explanation, the other emphasises evaluation of interventions. This essay analyses in what respects these views differ, and how they lead to opposite research hierarchies, with randomisation on top for evaluation and at bottom for discovery and explanation. The two views also differ strongly in their thinking about the role of prior specification of a research hypothesis. Hence, the essay explores the controversies surrounding subgroup analyses and multiplicity of analyses in observational research. This exploration leads to a rethinking of the universally accepted hierarchy of strength of study designs, which has the randomised trial on top: this hierarchy may be confounded by the prior odds of the research hypothesis. Finally, the strong opinions that are sometimes displayed in pitting the two types of medical science against each other may be explained by a difference in “loss function”: the difference in penalty for being wrong.

Further Evidence that Exclusive Breast-Feeding Reduces Mother-to-Child HIV Transmission Compared With Mixed Feeding:

The critical role of breast-feeding in improving infant and under-five-year survival in resource-limited settings has been well documented since the mid-1970s. A pooled analysis by the World Health Organization (WHO) of a number of studies on the impact of breast-feeding on child survival showed that the protective effect is strongest in the first six months of life, with a 4-6-fold survival benefit for breast-fed infants [1]. The benefit extends throughout the first year of life, with a 1.4-1.8-fold protective effect against mortality during months six through twelve.

Determining Origins and Causes of Childhood Obesity via Mendelian Randomization Analysis:

Childhood obesity has become a serious public health problem worldwide. The United States Centers for Disease Control and Prevention estimates that one in three children and adolescents are currently overweight/obese [1]. The adverse complications of childhood obesity on physical health and psychosocial development are tremendous [2]. Moreover, pediatric obesity may substantially increase future burden of cardiovascular disease and other morbidities in adulthood.

My picks from ScienceDaily

Antarctic Fish Species Adopts Winter Survival Strategy Similar To Hibernation:

Scientists have discovered an Antarctic fish species that adopts a winter survival strategy similar to hibernation. Scientists from British Antarctic Survey (BAS) and the University of Birmingham reveal, for the first time, that the Antarctic ‘cod’ Notothenia coriiceps effectively ‘puts itself on ice’ to survive the long Antarctic winter.

Mysterious Eel Fishery Decline Blamed On Changing Ocean Conditions:

American eels are fast disappearing from restaurant menus as stocks have declined sharply across the North Atlantic. While the reasons for the eel decline remain as mysterious as its long migrations, a recent study by a NOAA scientist and colleagues in Japan and the United Kingdom says shifts in ocean-atmosphere conditions may be a primary factor in declining reproduction and survival rates.

Low Maternal Education Linked To Intellectual Disabilities In Offspring:

By applying a public health approach, researchers at three universities have discovered a key indicator for increased risk of mental retardation in the general population. The study assessed population-level risk factors by linking birth records of 12-14-year-old children in Florida with their respective public school records, over the course of a school year.

Smoking Doesn’t Make You Happy:

If you are planning to ignore the messages of national No Smoking Day on 12th March by claiming that smoking is one of the few pleasures left to you, then recent research from the Peninsula Medical School in the South West of England may make you think again.

Mother-daughter Conflict, Low Serotonin Level May Be Deadly Combination:

A combination of negative mother-daughter relationships and low blood levels of serotonin, an important brain chemical for mood stability, may be lethal for adolescent girls, leaving them vulnerable to engage in self-harming behaviors such as cutting themselves.

Mercury Threatens Next Generation Of Loons:

A long-term study by the Wildlife Conservation Society, the BioDiversity Research Institute, and other organizations has found and confirmed that environmental mercury–much of which comes from human-generated emissions–is impacting both the health and reproductive success of common loons in the Northeast.

Mysteries Of Oceanic Bacteria Probed:

Microbes living in the oceans play a critical role in regulating Earth’s environment, but very little is known about their activities and how they work together to help control natural cycles of water, carbon and energy. A team of MIT researchers led by Professors Edward DeLong and Penny Chisholm is trying to change that.

Dissolved Organic Matter In Water Column May Influence Coral Health:

Bacterial communities endemic to healthy corals could change depending on the amount and type of natural and man-made dissolved organic matter in seawater, report researchers from The University of Texas at Austin Marine Science Institute and Mote Marine Laboratory in Sarasota, Florida.

Giant Panda Genome To Be Sequenced:

The International Giant Panda Genome Project has been launched. The goal of this project is to finish the sequencing and assembling of the draft sequence within six months, according to researchers with BGI-Shenzhen.

My picks from ScienceDaily

‘Power Napping’ In Pigeons:

In humans, as in all mammals, sleep consists of two phases: deep, dreamless slow-wave-sleep (SWS) alternates with dream phases, called Rapid Eye Movement (REM)-sleep. Although several studies suggest that information is processed and memories are consolidated during sleep, this remains a hotly debated topic in neurobiology. Comparative studies in birds may help to clarify the function of sleep by revealing overriding principles that would otherwise remain obscure if we only studied mammals. This is because birds are the only taxonomic group other than mammals to show both SWS and REM sleep.
Interestingly, the independent evolution of similar sleep states in birds and mammals might be related to the fact that each group also independently evolved large brains capable of performing complex cognitive processes. In their actual study, researchers from the Max-Planck Institute of Ornithology in Seewiesen, Germany showed for the first time that birds compensate for sleep loss in a manner similar to humans.

Tree Of Animal Life Has Branches Rearranged, By Evolutionary Biologists:

A study led by Brown University biologist Casey Dunn uses new genomics tools to answer old questions about animal evolution. The study is the most comprehensive animal phylogenomic research project to date, involving 40 million base pairs of new DNA data taken from 29 animal species. The study, which appears in Nature, settles some long-standing debates about the relationships between major groups of animals and offers up a few surprises.

Hobbits May Be Human After All:

RMIT University researchers have joined the worldwide debate over the hobbit-like fossils found on the Indonesian island of Flores, with a controversial new theory suggesting their primitive features are the result of a medical condition.

But see what Greg, Afarensis and Brian have to say about that paper!
Television Shows Can Affect Racial Judgments:

A new study reveals that viewers can be influenced by exposure to racial bias in the media, even without realizing it. Led by Dana Mastro of the University of Arizona, the study exposed participants to television clips where Latinos were portrayed in both flattering and unflattering ways.

Lowly Icelandic Midges Reveal Ecosystem’s Tipping Points:

The midges that periodically swarm by the billions from Iceland’s Lake Myvatn are a force of nature. At their peak, it is difficult to breathe without inhaling the bugs, which hatch and emerge from the lake in blizzard-like proportions. After their short adult life, their carcasses blanket the lake, and the dead flies confer so much nutrient on the surrounding landscape that the enhanced productivity can be measured by Earth-observing satellites.

Secrets Of Cooperation Between Trees And Fungi Revealed:

Plants gained their ancestral toehold on dry land with considerable help from their fungal friends. Now, millennia later, that partnership is being exploited as a strategy to bolster biomass production for next generation biofuels. The genetic mechanism of this kind of symbiosis, which contributes to the delicate ecological balance in healthy forests, also provides insights into plant health that may enable more efficient carbon sequestration and enhanced phytoremediation, using plants to clean up environmental contaminants.

My picks from ScienceDaily

Warming Climate May Cause Arctic Tundra To Burn:

Research from ancient sediment cores indicates that a warming climate could make the world’s arctic tundra far more susceptible to fires than previously thought. The findings are important given the potential for tundra fires to release organic carbon — which could add significantly to the amount of greenhouse gases already blamed for global warming.

Stop-And-Go Traffic: An Accident? Construction Work? No, Just Too Much Traffic:

A new study from a Japanese research group explains why we’re occasionally caught in traffic jams for no visible reason. The real origin of traffic jams often has nothing to do with obvious obstructions such as accidents or construction work but is simply the result of there being too many cars on the road.

See the video.
Most Physicians Sleep Fewer Hours Than Needed For Peak Performance, Report Says:

In a new survey, physicians report they are not getting the sleep they need to function at their best and current work schedules may contribute to their inadequate sleep. The survey, issued by the American College of Chest Physicians Sleep Institute (ACCP-SI), found that most physicians sleep fewer hours than needed for peak performance and nearly half of physicians believe their work schedules do not allow for adequate sleep. Results further indicated that, when compared to the general population, physicians reported more caffeine use but better overall health.

My picks from ScienceDaily

Giant Fossil Bats Out Of Africa, 35 Million Years Old:

When most of us think of Ancient Egypt, visions of pyramids and mummies fill our imaginations. For a team of paleontologists interested in fossil mammals, the Fayum district of Egypt summons an even older and equally impressive history that extends much further back in time than the Sphinx.

Are Wolves The Pronghorn’s Best Friend?:

As western states debate removing the gray wolf from protection under the Endangered Species Act, a new study by the Wildlife Conservation Society cautions that doing so may result in an unintended decline in another species: the pronghorn, a uniquely North American animal that resembles an African antelope.

Can Moths Or Butterflies Remember What They Learned As Caterpillars?:

Butterflies and moths are well known for their striking metamorphosis from crawling caterpillars to winged adults. In light of this radical change, not just in body form, but also in lifestyle, diet and dependence on particular sensory cues, it would seem unlikely that learned associations or memories formed at the larval or caterpillar stage could be accessible to the adult moth or butterfly. However, scientists at Georgetown University recently discovered that a moth can indeed remember what it learned as a caterpillar.

New and Exciting in PLoS Medicine and PLoS Biology

Last week’s crop of PLoS ONE articles enjoyed quite a nice buzz in the media and on the blogs. But today is a new week, and we start, as always with new articles in PLoS Medicine and PLoS Biology – here are some of the article that caught my attention:
Could an Open-Source Clinical Trial Data-Management System Be What We Have All Been Looking For:

In Europe, it is a legal requirement to conduct clinical trials in accordance with the International Conference on Harmonisation’s guidelines on good clinical practice (see http://www.ich.org/). A recent editorial reported that this directive has led to a decline in the number of trials being conducted by independent academic groups [1]. One possible reason for this is that reporting and documentation requirements are now so burdensome that the process has become unnecessarily complicated [2]. This is rather ironic, given that well-designed clinical trials should be amenable to very simple data handling and analysis [3]. Indeed the flowchart established by the CONSORT (Consolidated Standards of Reporting Trials) statement [4] for carrying out a properly randomised controlled trial has just four steps, which supports the approach of keeping it simple.

Effects of Selection for Honey Bee Worker Reproduction on Foraging Traits:

In social insects, the evolution of the worker caste and the regulation of reproductive behaviour by workers are poorly understood. Evolution is conservative and often proceeds by adapting an existing gene network to a new function. The “reproductive ground plan” hypothesis (RGPH) suggests that social insects evolved their queen and worker castes by modifying a gene network that once regulated the foraging and reproductive phases of solitary ancestors. In this model, queens retain characteristics of insects in their reproductive phase, whereas workers retain characteristics of the foraging phase. Moreover, the foraging behaviour of workers may also be regulated by the same genes that once controlled the switch between foraging and feeding young in the nest. We evaluated the RGPH by studying a line of honey bees selected for high rates of worker reproduction. We show that in this line workers forage late in life and some may never forage, supporting the idea that genes related to reproduction are also related to foraging. However, we found no support for recent suggestions that genes related to reproduction also regulate the foraging behaviour of individual workers: once they start foraging, our highly reproductive workers forage in the same way that unselected workers do.

Assessing Evidence for a Pervasive Alteration in Tropical Tree Communities:

Recent studies have reported major changes in mature tropical forests, with increases in both forest biomass and net primary productivity, as well as shifts in plant species composition that favour fast-growing species over slow-growing ones. These pervasive alterations were attributed to global environmental change, and may result in dramatic shifts in the functioning of tropical forest ecosystems. We reassessed these findings using a dataset of large permanent forest plots on three continents. We found that tree biomass increased at seven of our ten plots, and showed a large decrease at a single plot. Overall, this increase was significant, albeit lower than reported previously for Amazonian forests. At three sites for which we had data for multiple census intervals, we found no concerted increase in biomass gain, in conflict with the increased productivity hypothesis. With the exception of one plot, slow-growing species gained more biomass than either fast-growing species or the tree community as a whole. Hence, our results do not support the hypothesis that fast-growing species are consistently increasing in dominance in tropical tree communities. Overall, our results suggest that our plots may be simultaneously recovering from past disturbances and affected by changes in resource availability.

My picks from ScienceDaily

Fighting Australian Crayfish Do Not Forget The Face Of Foes:

The fighting Australian yabby, a type of crayfish, smaller than a lobster but similar in appearance, does not forget the face of its foes says new research from University of Melbourne zoologists. The two year study involving over 100 pairs of yabbies revealed that the species Cherax destructor is capable of facial recognition of individuals, particularly its opponents.

Why Juniper Trees Can Live On Less Water:

An ability to avoid the plant equivalent of vapor lock and a favorable evolutionary history may explain the unusual drought resistance of junipers, some varieties of which are now spreading rapidly in water-starved regions of the western United States, a Duke University study has found.

New Theory For Dogfish And Skate Population Outburst, Off New England Shore, US:

New research by scientists at the University of Maryland Center for Environmental Science Chesapeake Biological Laboratory questions the long-held belief that a lack of predators and competitors was the primary cause for the increase of skates and dogfish observed in Southern New England’s George’s Bank following overfishing of commercially important species in the 1980′s.

Evidence Of ‘Rain-making’ Bacteria Discovered In Atmosphere And Snow:

Brent Christner, LSU professor of biological sciences, in partnership with colleagues in Montana and France, recently found evidence that rain-making bacteria are widely distributed in the atmosphere. These biological particles could factor heavily into the precipitation cycle, affecting climate, agricultural productivity and even global warming. Christner and his colleagues published their results on Feb 29 in the journal Science.

Building Brains: Mammalian-like Neurogenesis In Fruit Flies:

The nerve cells in the brain of Drosophila are generated by neural stem cell-like progenitor cells called neuroblasts. In the currently accepted model of neurogenesis, these neuroblast divide asymmetrically both to self renew and to produce a smaller progenitor cell. This smaller cell then divides only once into two daughter cells, which receive cell fate determinants, causing them to exit the cell cycle and differentiate into postmitotic neural cells.

Enormous Jurassic Sea Predator, Pliosaur, Discovered In Norway:

Natural History Museum in Oslo, Norway has announced the discovery of one of the largest dinosaur-era marine reptiles ever found – an enormous sea predator known as a pliosaur estimated to be almost 15 meters (50 feet) feet long.

Chimps May Have A ‘Language-ready’ Brain:

An area of the brain involved in the planning and production of spoken and signed language in humans plays a similar role in chimpanzee communication, researchers report.

What Caused Westward Expansion In The United States?:

Western Expansion during the nineteenth century was an important determinant of geographic distribution and economic activity in the United States today. However, while explanations abound for why the migration occurred– from the low price of land to a pioneering spirit — little empirical work has been done to determine which specific market forces were the most important drivers.

New and Exciting in PLoS Genetics

Two of the papers published today in PLoS Genetics (now on the TOPAZ platform) got my attention:
Redundant Function of REV-ERBα and β and Non-Essential Role for Bmal1 Cycling in Transcriptional Regulation of Intracellular Circadian Rhythms:

Circadian clocks in plants, fungi, insects, and mammals all share a common transcriptional network architecture. At the cellular level, the mammalian clockwork consists of a core Per/Cry negative feedback loop and additional interlocking loops. We wished to address experimentally the contribution of the interlocking Bmal1 loop to clock function in mammals. Because behavioral rhythms do not always reflect cell-autonomous phenotypes and are subject to pleiotropic effects, we employed cell-based genetic approaches and monitored rhythms longitudinally using bioluminescent reporters of clock gene expression. We showed that REV-ERB repressors play a more prominent role than ROR activators in regulating the Bmal1 rhythm. However, significant rhythmicity remains even with constitutive expression of Bmal1, pointing to the resilience of the core loop to perturbations of the Bmal1 loop. We conclude that while the interlocking loop contributes to fine-tuning of the core loop, its primary function is to provide discrete waveforms of clock gene expression for control of local physiology. This study has important general implications not only for circadian biology across species, but also for the emerging field of systems biology that seeks to understand complex interactions in genetic networks.

Identification of the Yellow Skin Gene Reveals a Hybrid Origin of the Domestic Chicken:

Many bird species possess yellow skin and legs whereas other species have white or black skin color. Yellow or white skin is due to the presence or absence of carotenoids. The genetic basis underlying this diversity is unknown. Domestic chickens with yellow skin are homozygous for a recessive allele, and white skinned chickens carry the dominant allele. As a result, chickens represent an ideal model for analyzing genetic mechanism responsible for skin color variation. In this study we demonstrate that yellow skin is caused by regulatory mutation(s) that inhibit expression of the beta-carotene dioxygenase 2 (BCDO2) enzyme in skin, but not in other tissues. Because BCDO2 cleaves colorful carotenoids into colorless apocarotenoids, a reduction in expression of this gene produces yellow skin. This study also provides the first conclusive evidence of a hybrid origin of the domestic chicken. It has been generally assumed that the red junglefowl is the sole ancestor of the domestic chicken. A phylogenetic analysis, however, demonstrates that though the white skin allele originates from the red junglefowl, the yellow skin allele originates from a different species, most likely the grey junglefowl. This result significantly advances our understanding of chicken domestication.

Greg Laden explains.

My picks from ScienceDaily

This Is Your Brain On Jazz: Researchers Use MRI To Study Spontaneity, Creativity:

A pair of Johns Hopkins and government scientists have discovered that when jazz musicians improvise, their brains turn off areas linked to self-censoring and inhibition, and turn on those that let self-expression flow.

More coverage from Smooth Pebbles, Mind Hacks, Wired Science, Neurophilosophy, Science A Go Go, PsychCentral and The Rehearsal Studio
Evolution Of Aversion: Why Even Children Are Fearful Of Snakes:

Some of the oldest tales and wisest mythology allude to the snake as a mischievous seducer, dangerous foe or powerful iconoclast; however, the legend surrounding this proverbial predator may not be based solely on fantasy. As scientists from the University of Virginia recently discovered, the common fear of snakes is most likely intrinsic.

By Sixth Grade Nearly One In Six Children Are Alcohol Users, Study Shows:

A study by the University of Minnesota School of Public Health and the University of Florida suggests that ‘tweens’ should receive alcohol prevention programs prior to sixth grade, when nearly one in six children are already alcohol users.

Chad Orzel comments.
Polluted Prey Causes Wild Birds To Change Their Tune:

Considerable attention has been paid to the effects of endocrine disrupting chemicals in aquatic environments, but rather less attention has been given to routes of contamination on land. A new study by researchers at Cardiff University, reveals that wild birds foraging on invertebrates contaminated with environmental pollutants, show marked changes in both brain and behaviour: male birds exposed to this pollution develop more complex songs, which are actually preferred by the females, even though these same males usually show reduced immune function compared to controls.

Catching Rats’ Twitchy Whiskers In Action:

Rats use their whiskers in a way that is closely related to the human sense of touch: Just as humans move their fingertips across a surface to perceive shapes and textures, rats twitch their whiskers to achieve the same goal. Now, in a finding that could help further understanding of perception across species, MIT neuroscientists have used high-speed video to reveal rat whiskers in action and show the tiny movements that underlie the rat’s perception of its tactile environment.

Spread Of Bird Flu Strains Slowed At Some Borders:

Several strains of the bird flu virus that raged across southern China were blocked from entering Thailand and Vietnam, UC Irvine researchers have discovered. This first-ever statistical analysis of influenza A H5N1′s genetic diversity helps scientists better understand how the virus migrates and could, in the future, help health officials determine whether efforts to thwart its spread were successful.

From Sharks To Microbes, Key Data At Central Pacific’s Line Islands Archipelago Captured:

An ambitious expedition led by scientists at Scripps Institution of Oceanography at UC San Diego to a chain of little-known islands in the central Pacific Ocean has yielded an unprecedented wealth of information about coral reefs and threats from human activities. The exploration of four atolls in the Line Islands, part of a chain approximately a thousand miles south of Hawaii, has produced the first study of coral reefs comprehensively spanning organisms from microbes to sharks. This in-depth description was replicated across a gradient of human impacts, from uninhabited Kingman Reef to Kiritimati, also called Christmas Island, with a population of 5,000 people.

More from Resilience Science

My picks from ScienceDaily

Bats Use Magnetic Substance As Internal Compass To Help Them Navigate:

They may not be on most people’s list of most attractive species, but bats definitely have animal magnetism. Researchers from the Universities of Leeds and Princeton have discovered that bats use a magnetic substance in their body called magnetite as an ‘internal compass’ to help them navigate.

Or, if you prefer a much livelier take, with context, check out Pondering Pikaia
Why Do We Love Babies? Parental Instinct Region Found In The Brain:

Why do we almost instinctively treat babies as special, protecting them and enabling them to survive? Darwin originally pointed out that there is something about infants which prompts adults to respond to and care for them which allows our species to survive. Nobel-Prize-winning zoologist Konrad Lorenz proposed that it is the specific structure of the infant face, including a relatively large head and forehead, large and low lying eyes and bulging cheek region, that serves to elicit these parental responses. But the biological basis for this has remained elusive.

Dave Munger explains.
Antidepressants Only Benefit Certain Depressed Patients, Study Suggests:

A new study suggests that antidepressants only benefit some, very severely depressed patients. “New generation” antidepressants, such as fluoxetine (Prozac) are widely prescribed for the treatment of clinical depression. However some studies have suggested that these drugs do not help the majority of depressed people get better by very much. Irving Kirsch, from the University of Hull, and his colleagues, studied this question in closer detail, looking at whether a patient’s response to antidepressant therapy depends on how badly depressed they are to start out with.

More coverage by Ben Goldacre, David Dobbs, Kevin Drum, James Hrynyshyn, Henry Gee, Greg Laden, Jonah Lehrer and Socratic Gadfly.
How Skin Color Is Determined:

Skin color is one of the most visible indicators that helps distinguish human appearance, and a new study provides more detail as to how one protein helps produce this wide palette.

Children Who Do Not Get Enough Sleep Sustain More Injuries:

Lack of adequate sleep can lead to increased injuries among preschool children, new research shows. This study shows that the average number of injuries during the preschool years is two times higher for children who don’t get enough sleep each day as described by their mothers.

Lemurs’ Evolutionary History May Shed Light On Our Own:

After swabbing the cheeks of more than 200 lemurs and related primates to collect their DNA, researchers at the Duke Institute for Genome Sciences & Policy (IGSP) and Duke Lemur Center now have a much clearer picture of their evolutionary family tree.

Congratulations to Karen James!

Excitement on science blogs! Karen James of the Beagle Project Blog has just today published a paper in PLoS ONE:
Diversity Arrays Technology (DArT) for Pan-Genomic Evolutionary Studies of Non-Model Organisms:

Background
High-throughput tools for pan-genomic study, especially the DNA microarray platform, have sparked a remarkable increase in data production and enabled a shift in the scale at which biological investigation is possible. The use of microarrays to examine evolutionary relationships and processes, however, is predominantly restricted to model or near-model organisms.
Methodology/Principal Findings
This study explores the utility of Diversity Arrays Technology (DArT) in evolutionary studies of non-model organisms. DArT is a hybridization-based genotyping method that uses microarray technology to identify and type DNA polymorphism. Theoretically applicable to any organism (even one for which no prior genetic data are available), DArT has not yet been explored in exclusively wild sample sets, nor extensively examined in a phylogenetic framework. DArT recovered 1349 markers of largely low copy-number loci in two lineages of seed-free land plants: the diploid fern Asplenium viride and the haploid moss Garovaglia elegans. Direct sequencing of 148 of these DArT markers identified 30 putative loci including four routinely sequenced for evolutionary studies in plants. Phylogenetic analyses of DArT genotypes reveal phylogeographic and substrate specificity patterns in A. viride, a lack of phylogeographic pattern in Australian G. elegans, and additive variation in hybrid or mixed samples.
Conclusions/Significance
These results enable methodological recommendations including procedures for detecting and analysing DArT markers tailored specifically to evolutionary investigations and practical factors informing the decision to use DArT, and raise evolutionary hypotheses concerning substrate specificity and biogeographic patterns. Thus DArT is a demonstrably valuable addition to the set of existing molecular approaches used to infer biological phenomena such as adaptive radiations, population dynamics, hybridization, introgression, ecological differentiation and phylogeography.

Have no idea what it all means? Be patient. Karen will explain it all on the Beagle Project Blog in a day or two….

New and Exciting in PLoS ONE

There are 48 new articles published this week in PLoS ONE. It’s hard to choose just a couple to highlight, so look around for what interests you (avian flu, the Plague?). How about these titles that piqued my interest:
Neural Substrates of Spontaneous Musical Performance: An fMRI Study of Jazz Improvisation:

To investigate the neural substrates that underlie spontaneous musical performance, we examined improvisation in professional jazz pianists using functional MRI. By employing two paradigms that differed widely in musical complexity, we found that improvisation (compared to production of over-learned musical sequences) was consistently characterized by a dissociated pattern of activity in the prefrontal cortex: extensive deactivation of dorsolateral prefrontal and lateral orbital regions with focal activation of the medial prefrontal (frontal polar) cortex. Such a pattern may reflect a combination of psychological processes required for spontaneous improvisation, in which internally motivated, stimulus-independent behaviors unfold in the absence of central processes that typically mediate self-monitoring and conscious volitional control of ongoing performance. Changes in prefrontal activity during improvisation were accompanied by widespread activation of neocortical sensorimotor areas (that mediate the organization and execution of musical performance) as well as deactivation of limbic structures (that regulate motivation and emotional tone). This distributed neural pattern may provide a cognitive context that enables the emergence of spontaneous creative activity.

A Specific and Rapid Neural Signature for Parental Instinct:

Darwin originally pointed out that there is something about infants which prompts adults to respond to and care for them, in order to increase individual fitness, i.e. reproductive success, via increased survivorship of one’s own offspring. Lorenz proposed that it is the specific structure of the infant face that serves to elicit these parental responses, but the biological basis for this remains elusive. Here, we investigated whether adults show specific brain responses to unfamiliar infant faces compared to adult faces, where the infant and adult faces had been carefully matched across the two groups for emotional valence and arousal, as well as size and luminosity. The faces also matched closely in terms of attractiveness. Using magnetoencephalography (MEG) in adults, we found that highly specific brain activity occurred within a seventh of a second in response to unfamiliar infant faces but not to adult faces. This activity occurred in the medial orbitofrontal cortex (mOFC), an area implicated in reward behaviour, suggesting for the first time a neural basis for this vital evolutionary process. We found a peak in activity first in mOFC and then in the right fusiform face area (FFA). In mOFC the first significant peak (p<0.001) in differences in power between infant and adult faces was found at around 130 ms in the 10-15 Hz band. These early differences were not found in the FFA. In contrast, differences in power were found later, at around 165 ms, in a different band (20-25 Hz) in the right FFA, suggesting a feedback effect from mOFC. These findings provide evidence in humans of a potential brain basis for the "innate releasing mechanisms" described by Lorenz for affection and nurturing of young infants. This has potentially important clinical applications in relation to postnatal depression, and could provide opportunities for early identification of families at risk.

Time Pressure Modulates Electrophysiological Correlates of Early Visual Processing:

Reactions to sensory events sometimes require quick responses whereas at other times they require a high degree of accuracy-usually resulting in slower responses. It is important to understand whether visual processing under different response speed requirements employs different neural mechanisms. We asked participants to classify visual patterns with different levels of detail as real-world or non-sense objects. In one condition, participants were to respond immediately, whereas in the other they responded after a delay of 1 second. As expected, participants performed more accurately in delayed response trials. This effect was pronounced for stimuli with a high level of detail. These behavioral effects were accompanied by modulations of stimulus related EEG gamma oscillations which are an electrophysiological correlate of early visual processing. In trials requiring speeded responses, early stimulus-locked oscillations discriminated real-world and non-sense objects irrespective of the level of detail. For stimuli with a higher level of detail, oscillatory power in a later time window discriminated real-world and non-sense objects irrespective of response speed requirements. Thus, it seems plausible to assume that different response speed requirements trigger different dynamics of processing.

Generalization Mediates Sensitivity to Complex Odor Features in the Honeybee:

Animals use odors as signals for mate, kin, and food recognition, a strategy which appears ubiquitous and successful despite the high intrinsic variability of naturally-occurring odor quantities. Stimulus generalization, or the ability to decide that two objects, though readily distinguishable, are similar enough to afford the same consequence [1], could help animals adjust to variation in odor signals without losing sensitivity to key inter-stimulus differences. The present study was designed to investigate whether an animal’s ability to generalize learned associations to novel odors can be influenced by the nature of the associated outcome. We use a classical conditioning paradigm for studying olfactory learning in honeybees [2] to show that honeybees conditioned on either a fixed- or variable-proportion binary odor mixture generalize learned responses to novel proportions of the same mixture even when inter-odor differences are substantial. We also show that the resulting olfactory generalization gradients depend critically on both the nature of the stimulus-reward paradigm and the intrinsic variability of the conditioned stimulus. The reward dependency we observe must be cognitive rather than perceptual in nature, and we argue that outcome-dependent generalization is necessary for maintaining sensitivity to inter-odor differences in complex olfactory scenes.

Memory in Microbes: Quantifying History-Dependent Behavior in a Bacterium:

Memory is usually associated with higher organisms rather than bacteria. However, evidence is mounting that many regulatory networks within bacteria are capable of complex dynamics and multi-stable behaviors that have been linked to memory in other systems. Moreover, it is recognized that bacteria that have experienced different environmental histories may respond differently to current conditions. These “memory” effects may be more than incidental to the regulatory mechanisms controlling acclimation or to the status of the metabolic stores. Rather, they may be regulated by the cell and confer fitness to the organism in the evolutionary game it participates in. Here, we propose that history-dependent behavior is a potentially important manifestation of memory, worth classifying and quantifying. To this end, we develop an information-theory based conceptual framework for measuring both the persistence of memory in microbes and the amount of information about the past encoded in history-dependent dynamics. This method produces a phenomenological measure of cellular memory without regard to the specific cellular mechanisms encoding it. We then apply this framework to a strain of Bacillus subtilis engineered to report on commitment to sporulation and degradative enzyme (AprE) synthesis and estimate the capacity of these systems and growth dynamics to ‘remember’ 10 distinct cell histories prior to application of a common stressor. The analysis suggests that B. subtilis remembers, both in short and long term, aspects of its cell history, and that this memory is distributed differently among the observables. While this study does not examine the mechanistic bases for memory, it presents a framework for quantifying memory in cellular behaviors and is thus a starting point for studying new questions about cellular regulation and evolutionary strategy.

Crayfish Recognize the Faces of Fight Opponents:

The capacity to associate stimuli underlies many cognitive abilities, including recognition, in humans and other animals. Vertebrates process different categories of information separately and then reassemble the distilled information for unique identification, storage and recall. Invertebrates have fewer neural networks and fewer neural processing options so study of their behavior may reveal underlying mechanisms still not fully understood for any animal. Some invertebrates form complex social colonies and are capable of visual memory-bees and wasps, for example. This ability would not be predicted in species that interact in random pairs without strong social cohesion; for example, crayfish. They have chemical memory but the extent to which they remember visual features is unknown. Here we demonstrate that the crayfish Cherax destructor is capable of visual recognition of individuals. The simplicity of their interactions allowed us to examine the behavior and some characteristics of the visual features involved. We showed that facial features are learned during face-to-face fights, that highly variable cues are used, that the type of variability is important, and that the learning is context-dependent. We also tested whether it is possible to engineer false identifications and for animals to distinguish between twin opponents.

The Blind Watchmaker Network: Scale-Freeness and Evolution:

It is suggested that the degree distribution for networks of the cell-metabolism for simple organisms reflects a ubiquitous randomness. This implies that natural selection has exerted no or very little pressure on the network degree distribution during evolution. The corresponding random network, here termed the blind watchmaker network has a power-law degree distribution with an exponent γ≥2. It is random with respect to a complete set of network states characterized by a description of which links are attached to a node as well as a time-ordering of these links. No a priory assumption of any growth mechanism or evolution process is made. It is found that the degree distribution of the blind watchmaker network agrees very precisely with that of the metabolic networks. This implies that the evolutionary pathway of the cell-metabolism, when projected onto a metabolic network representation, has remained statistically random with respect to a complete set of network states. This suggests that even a biological system, which due to natural selection has developed an enormous specificity like the cellular metabolism, nevertheless can, at the same time, display well defined characteristics emanating from the ubiquitous inherent random element of Darwinian evolution. The fact that also completely random networks may have scale-free node distributions gives a new perspective on the origin of scale-free networks in general.

Quantifying Variability of Avian Colours: Are Signalling Traits More Variable?:

Increased variability in sexually selected ornaments, a key assumption of evolutionary theory, is thought to be maintained through condition-dependence. Condition-dependent handicap models of sexual selection predict that (a) sexually selected traits show amplified variability compared to equivalent non-sexually selected traits, and since males are usually the sexually selected sex, that (b) males are more variable than females, and (c) sexually dimorphic traits more variable than monomorphic ones. So far these predictions have only been tested for metric traits. Surprisingly, they have not been examined for bright coloration, one of the most prominent sexual traits. This omission stems from computational difficulties: different types of colours are quantified on different scales precluding the use of coefficients of variation. Based on physiological models of avian colour vision we develop an index to quantify the degree of discriminable colour variation as it can be perceived by conspecifics. A comparison of variability in ornamental and non-ornamental colours in six bird species confirmed (a) that those coloured patches that are sexually selected or act as indicators of quality show increased chromatic variability. However, we found no support for (b) that males generally show higher levels of variability than females, or (c) that sexual dichromatism per se is associated with increased variability. We show that it is currently possible to realistically estimate variability of animal colours as perceived by them, something difficult to achieve with other traits. Increased variability of known sexually-selected/quality-indicating colours in the studied species, provides support to the predictions borne from sexual selection theory but the lack of increased overall variability in males or dimorphic colours in general indicates that sexual differences might not always be shaped by similar selective forces.

Frequency and Density-Dependent Selection on Life-History Strategies – A Field Experiment:

Negative frequency-dependence, which favors rare genotypes, promotes the maintenance of genetic variability and is of interest as a potential explanation for genetic differentiation. Density-dependent selection may also promote cyclic changes in frequencies of genotypes. Here we show evidence for both density-dependent and negative frequency-dependent selection on opposite life-history tactics (low or high reproductive effort, RE) in the bank vole (Myodes glareolus). Density-dependent selection was evident among the females with low RE, which were especially favored in low densities. Instead, both negative frequency-dependent and density-dependent selection were shown in females with high RE, which were most successful when they were rare in high densities. Furthermore, selection at the individual level affected the frequencies of tactics at the population level, so that the frequency of the rare high RE tactic increased significantly at high densities. We hypothesize that these two selection mechanisms (density- and negative frequency-dependent selection) may promote genetic variability in cyclic mammal populations. Nevertheless, it remains to be determined whether the origin of genetic variance in life-history traits is causally related to density variation (e.g. population cycles).

Effectiveness of Journal Ranking Schemes as a Tool for Locating Information:

The rise of electronic publishing [1], preprint archives, blogs, and wikis is raising concerns among publishers, editors, and scientists about the present day relevance of academic journals and traditional peer review [2]. These concerns are especially fuelled by the ability of search engines to automatically identify and sort information [1]. It appears that academic journals can only remain relevant if acceptance of research for publication within a journal allows readers to infer immediate, reliable information on the value of that research. Here, we systematically evaluate the effectiveness of journals, through the work of editors and reviewers, at evaluating unpublished research. We find that the distribution of the number of citations to a paper published in a given journal in a specific year converges to a steady state after a journal-specific transient time, and demonstrate that in the steady state the logarithm of the number of citations has a journal-specific typical value. We then develop a model for the asymptotic number of citations accrued by papers published in a journal that closely matches the data. Our model enables us to quantify both the typical impact and the range of impacts of papers published in a journal. Finally, we propose a journal-ranking scheme that maximizes the efficiency of locating high impact research.

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My picks from ScienceDaily

Religion Colors Americans’ Views Of Nanotechnology:

Is nanotechnology morally acceptable? For a significant percentage of Americans, the answer is no, according to a recent survey of Americans’ attitudes about the science of the very small.

Male Fertility May Be Harmed By Mix Of Endocrine Disrupters:

Endocrine-disrupting chemicals, which are harmless individually in small doses, can together be a dangerous cocktail. Concurrent exposure to several endocrine-disrupting substances may, among other things, result in malformed sexual organs. Risk assessments of chemical substances should therefore take potential cocktail effects into account.

Two Oxygenation Events In Ancient Oceans Sparked Spread Of Complex Life:

The rise of oxygen and the oxidation of deep oceans between 635 and 551 million years ago may have had an impact on the increase and spread of the earliest complex life, including animals, according to a new study.

Krill Discovered Living In The Antarctic Abyss:

Scientists have discovered Antarctic krill (Euphausia superba) living and feeding down to depths of 3000 metres in the waters around the Antarctic Peninsula. Until now this shrimp-like crustacean was thought to live only in the upper ocean. The discovery completely changes scientists’ understanding of the major food source for fish, squid, penguins, seals and whales.

Empty Nest Syndrome May Not Be Bad After All, Study Finds:

One day they are crawling, the next day they are driving and then suddenly they aren’t kids anymore. As children reach adulthood, the parent-child relationship changes as parents learn to adapt to newly independent children. A new study by a University of Missouri professor explored the differences in how mothers and fathers interacted with their young adult children. She found there were few differences in the way mothers and fathers felt and that many of the changes were positive, despite the perception that mothers in particular fall apart and experience the so-called empty nest syndrome.

Zoologists Challenge Longstanding Theory That ‘Eyespots’ Mimic The Eyes Of Predators’ Enemies:

Circular markings on creatures such as butterflies are effective against predators because they are conspicuous features, not because they mimic the eyes of the predators’ own enemies, according to research in the journal, Behavioral Ecology*. Zoologists based at the University of Cambridge challenge the 150-year-old theory about why these markings are effective against predators.

Busy Beavers Can Help Ease Drought:

They may be considered pests, but beaver can help mitigate the effects of drought, and because of that, their removal from wetlands to accommodate industrial, urban and agricultural demands should be avoided, according to a new University of Alberta study.

My picks from ScienceDaily

Snakes Locate Prey Through Vibration Waves:

It is often believed that snakes cannot hear. This presumption is fed by the fact that snakes lack an outer ear and that scientific evidence of snakes responding to sound is scarce. Snakes do, however, possess an inner ear with a functional cochlea.

Masters Of Disguise: Secrets Of Nature’s ‘Great Pretenders’ Revealed:

A gene which helps a harmless African butterfly ward off predators by giving it wing patterns like those of toxic species, has been identified. The mocker swallowtail butterfly, Papilio dardanus, is unusual because it emerges from its chrysalis with one of a large number of different possible wing patterns and colours. This is different from most butterfly species which are identified by a common wing pattern and colour. Furthermore, some of the different patterns that the mocker swallowtail exhibits mimic those of poisonous species, which affords this harmless insect a valuable disguise which scares off predators.

Salamanders Are ‘Keystone’ Species: Headwater Streams Critical In Food Chain:

University of Missouri scientist Ray Semlitsch studies creatures most people don’t ever see. These creatures are active only at night and thrive in the shallow, cool, wet surroundings of headwater streams, an oft-overlooked biological environment.

New and Exciting in PLoS Medicine, PLoS Biology and PLoS ONE

There are a bunch of new papers in PLoS Biology and PLoS Medicine and, somewhat out of usual schedule, in PLoS ONE. So, check out these and then look around for more:
Does Mutation Rate Depend on Itself:

Many a research paper, textbook chapter, and grant proposal has begun with the phrase “Mutation is the ultimate source of genetic variation.” Implicit in this phrase is the assumption that genetic variation is required for evolution. Without mutation, evolution would not be possible, and life itself could never have arisen in the first place. However, there is overwhelming evidence that the great majority of mutations with detectable effects are harmful [1-3]. Deleterious mutations are the price we living organisms pay for the ability to evolve.

Understanding the Web of Life: The Birds, the Bees, and Sex with Aliens:

When I was in school, I learned about a linear food chain in which, for example, flowers provide food for bees, which in turn are eaten by birds. The implications of this model are clear: if bees were to vanish, birds would starve and flowers would not be pollinated. Whether this concept was a hangover from the old idea of the great chain of being (scala naturæ) or a simplification deemed necessary for unsophisticated school children is unclear. Nevertheless, despite the appeal of this simple caricature, it couldn’t be further from the truth in most of the world’s ecosystems. Birds feed on a variety of plants and animals, and are themselves fed upon by mammals, other birds, a diverse array of parasites, and eventually carrion feeders. It takes little more than a passing glance at the natural world to notice that complexity is the rule, rather than the exception. Describing this complexity and understanding its importance, however, is anything but simple. Ecologists have for a long time struggled to find consistent patterns in the structure of complex webs of interacting species from disparate ecosystems. However, recent empirical and theoretical breakthroughs have begun to shed light on the structure of the web of life that connects living things, and the vulnerability of this web to perturbations such as the introduction of invasive alien species.

The Fall and Rise of US Inequities in Premature Mortality: 1960-2002:

Debates exist as to whether, as overall population health improves, the absolute and relative magnitude of income- and race/ethnicity-related health disparities necessarily increase–or derease. We accordingly decided to test the hypothesis that health inequities widen–or shrink–in a context of declining mortality rates, by examining annual US mortality data over a 42 year period. Using US county mortality data from 1960-2002 and county median family income data from the 1960-2000 decennial censuses, we analyzed the rates of premature mortality (deaths among persons under age 65) and infant death (deaths among persons under age 1) by quintiles of county median family income weighted by county population size. Between 1960 and 2002, as US premature mortality and infant death rates declined in all county income quintiles, socioeconomic and racial/ethnic inequities in premature mortality and infant death (both relative and absolute) shrank between 1966 and 1980, especially for US populations of color; thereafter, the relative health inequities widened and the absolute differences barely changed in magnitude. Had all persons experienced the same yearly age-specific premature mortality rates as the white population living in the highest income quintile, between 1960 and 2002, 14% of the white premature deaths and 30% of the premature deaths among populations of color would not have occurred. The observed trends refute arguments that health inequities inevitably widen–or shrink–as population health improves. Instead, the magnitude of health inequalities can fall or rise; it is our job to understand why.

The following three articles, two PLoS ONE research papers and a review in PLoS Biology are part of the same “package”, which, I hear, may be controversial in some circles (and I hope the expert bloggers will enlighten us all about it):
Shifting Baselines, Local Impacts, and Global Change on Coral Reefs:

Imagine trying to understand the ecology of tropical rainforests by studying environmental changes and interactions among the surviving plants and animals on a vast cattle ranch in the center of a deforested Amazon, without any basic data on how the forest worked before it was cleared and burned. The soil would be baked dry or eroded away and the amount of rainfall would be greatly decreased. Most of the fantastic biodiversity would be gone. The trees would be replaced by grasses or soybeans, the major grazers would be leaf-cutter ants and cattle, and the major predators would be insects, rodents, and hawks. Ecologists could do experiments on the importance of cattle for the maintenance of plant species diversity, but the results would be meaningless for understanding the rainforest that used to be or how to restore it in the future.
Fortunately, ecologists began to carefully describe tropical forests more than a century ago, and vast areas of largely intact forests have persisted until today, so there are meaningful baselines for comparison. Networks of 50-hectare plots are monitored around the world [1], and decades of experiments have helped to elucidate ecological mechanisms in these relatively pristine forests [2]. But the situation is very different for the oceans, because degradation of entire ecosystems has been more pervasive than on land [3] and underwater observations began much more recently. Monitoring of benthic ecosystems is commonly limited to small intertidal quadrats, and there is nothing like the high-resolution global monitoring network for tropical forests for any ocean ecosystem.
This lack of a baseline for pristine marine ecosystems is particularly acute for coral reefs, the so-called rainforests of the sea, which are the most diverse marine ecosystems and among the most threatened [4-8].

Baselines and Degradation of Coral Reefs in the Northern Line Islands:

Effective conservation requires rigorous baselines of pristine conditions to assess the impacts of human activities and to evaluate the efficacy of management. Most coral reefs are moderately to severely degraded by local human activities such as fishing and pollution as well as global change, hence it is difficult to separate local from global effects. To this end, we surveyed coral reefs on uninhabited atolls in the northern Line Islands to provide a baseline of reef community structure, and on increasingly populated atolls to document changes associated with human activities. We found that top predators and reef-building organisms dominated unpopulated Kingman and Palmyra, while small planktivorous fishes and fleshy algae dominated the populated atolls of Tabuaeran and Kiritimati. Sharks and other top predators overwhelmed the fish assemblages on Kingman and Palmyra so that the biomass pyramid was inverted (top-heavy). In contrast, the biomass pyramid at Tabuaeran and Kiritimati exhibited the typical bottom-heavy pattern. Reefs without people exhibited less coral disease and greater coral recruitment relative to more inhabited reefs. Thus, protection from overfishing and pollution appears to increase the resilience of reef ecosystems to the effects of global warming.

Microbial Ecology of Four Coral Atolls in the Northern Line Islands:

Microbes are key players in both healthy and degraded coral reefs. A combination of metagenomics, microscopy, culturing, and water chemistry were used to characterize microbial communities on four coral atolls in the Northern Line Islands, central Pacific. Kingman, a small uninhabited atoll which lies most northerly in the chain, had microbial and water chemistry characteristic of an open ocean ecosystem. On this atoll the microbial community was equally divided between autotrophs (mostly Prochlorococcus spp.) and heterotrophs. In contrast, Kiritimati, a large and populated (~5500 people) atoll, which is most southerly in the chain, had microbial and water chemistry characteristic of a near-shore environment. On Kiritimati, there were 10 times more microbial cells and virus-like particles in the water column and these microbes were dominated by heterotrophs, including a large percentage of potential pathogens. Culturable Vibrios were common only on Kiritimati. The benthic community on Kiritimati had the highest prevalence of coral disease and lowest coral cover. The middle atolls, Palmyra and Tabuaeran, had intermediate densities of microbes and viruses and higher percentages of autotrophic microbes than either Kingman or Kiritimati. The differences in microbial communities across atolls could reflect variation in 1) oceaonographic and/or hydrographic conditions or 2) human impacts associated with land-use and fishing. The fact that historically Kingman and Kiritimati did not differ strongly in their fish or benthic communities (both had large numbers of sharks and high coral cover) suggest an anthropogenic component in the differences in the microbial communities. Kingman is one of the world’s most pristine coral reefs, and this dataset should serve as a baseline for future studies of coral reef microbes. Obtaining the microbial data set, from atolls is particularly important given the association of microbes in the ongoing degradation of coral reef ecosystems worldwide.

My picks from ScienceDaily

Early Experience Affects Where Birds Breed For Life: What Happens If Habitat Changes?:

How young migratory birds choose the nesting location of their first breeding season has been something of a mystery in the bird world. But a new University of Maryland/National Zoo study of the American redstart suggests that the environmental conditions the birds face in their first year may help determine where they breed for the rest of their lives, a factor that could significantly affect the population as climate change makes their winter habitats hotter and drier.

Ancient Puzzle Solved In Fossils From Canadian Rockies, Dating To Cambrian Explosion:

Geologists at the University of Leicester have solved a puzzle found in rocks half a billion years old. Some of the most important fossil beds in the world are the Burgess Shales in the Canadian Rockies. Once an ancient sea bed, they were formed shortly after life suddenly became more complex and diverse — the so-called Cambrian explosion — and are of immense scientific interest.

Python Snakes, An Invasive Species In Florida, Could Spread To One Third Of US:

Burmese pythons–an invasive species in south Florida–could find comfortable climatic conditions in roughly a third of the United States according to new “climate maps” developed by the U.S. Geological Survey (USGS). Although other factors such as type of food available and suitable shelter also play a role, Burmese pythons and other giant constrictor snakes have shown themselves to be highly adaptable to new environments.

Small Sea Creatures May Be The ‘Canaries In The Coal Mine’ Of Climate Change:

As oceans warm and become more acidic, ocean creatures are undergoing severe stress and entire food webs are at risk, according to scientists at a press briefing this morning at the annual meeting of the American Association for the Advancement of Science in Boston.

Space Tourism To Rocket In This Century, Researchers Predict:

Seeking an out-of-this-world travel destination? Outer space will rocket into reality as “the” getaway of this century, according to researchers at the University of Delaware and the University of Rome La Sapienza. In fact, the “final frontier” could begin showing up in travel guides by 2010, they predict.

Bacteria Can Be Made To Spin Spider Silk Through Understanding Of Big Molecules:

Biological and medical research is on the threshold of a new era based on better understanding of how large organic molecules bind together and recognise each other. There is great potential for exploiting the molecular docking processes that are commonplace in all organisms to develop new drugs that act more specifically without adverse side effects, and construct novel materials by mimicking nature.

Worm Defecation Holds Clues To Widespread Cell-to-cell Communication Process:

The focus of two recent Nobel prizes, a species of roundworm has made possible another advance in the understanding of how cells talk to one another, according to a study published online Feb. 21 in the journal Current Biology. In 2002, researchers won the Nobel Prize for Medicine for work in the roundworm Caenorhabditis elegans (C. elegans) on the genetics of how cells “decide” to self-destruct, a topic now central to human cancer research. Another team won in 2006 for the discovery in C. elegans of an ancient defense mechanism against attempts by viruses to disrupt cells’ genetic machinery.

Inside The Head Of An Ape:

Do apes have imagination? How do they understand pictures? A years-long study of apes performed by cognitive scientist Tomas Persson shows, among other things, that it doesn’t take a human brain to understand pictures as being a representation. Persson’s dissertation, which is now being submitted at Lund University, is the first one in Sweden to focus entirely on the thinking of apes.

Unveiling The Underwater Ways Of The White Shark:

It’s hard to study a creature when you only catch fleeting glimpses of it. Up until recently, that was one of the big stumbling blocks for marine biologists and ecologists, but advances in electronic tracking technology have allowed them to peer farther across, and deeper under, the surface of the oceans than ever before.

My picks from ScienceDaily

Saving The Rainforest With … Toys?:

Villagers in tiny communities including Guayabo, Sawacito and Mahor, in the rainforest of northeastern Honduras, used to take part in the rampant illegal trade in mahogany, but recently they have formed a cooperative and learned to harvest the prized wood in sustainable ways. Now, they mostly use trees that have fallen naturally or harvest them in a sustainable way from around the fringes of the nearby Rio Platano Biosphere Reserve, and remove planks from the forest, first on their backs, then on muleback to avoid the disruption caused by heavy machinery.

Can Exposure To Intense Underwater Sound Result In Death Of Whales?:

NOAA Fisheries Service is looking at how marine mammals react to underwater sound. Increasing evidence suggests that exposure to intense underwater sound in some settings may cause certain marine mammals to strand and ultimately die. Some of these strandings are associated with mid-frequency active (MFA) military sonar, and most have involved beaked whales; the dominant species is Cuvier’s beaked whale (Ziphius cavirostris), but the genus (Mesoplodon) has also been involved.

Mysterious Sea Creatures Found In Antarctic Waters:

The return of the last of three Antarctic marine science research vessels marks the culmination of one of Australia’s most ambitious International Polar Year projects, a census of life in the icy Southern Ocean known as the Collaborative East Antarctic Marine Census (CEAMARC). Australia’s Aurora Australis and collaborating vessels L’Astrolabe (France) and Umitaka Maru (Japan) have returned from the Southern Ocean, their decks overflowing with a vast array of ocean life including a number of previously unknown species collected from the cold waters near the East Antarctic land mass.

No Easy Answers In Evolution Of Human Language:

The evolution of human speech was far more complex than is implied by some recent attempts to link it to a specific gene, says Robert Berwick, professor of computational linguistics at MIT. Berwick will describe his ideas about language in a session at the annual meeting of the American Association for the Advancement of Science on Feb. 17. The session is called “Mind of a Toolmaker,” and explores the use of evolutionary research in understanding human abilities.

Is That Sea Otter Stealing Your Lunch — Or Making It?:

Hunted to near extinction, sea otters are making a steady comeback along the Pacific coast. Their reintroduction, however, is expected to reduce the numbers of several key species of commercially valuable shellfish dramatically, such as sea urchins and geoducks.

Like Owner, Like Dog: One Third Of US Dogs Are Obese, Cats Also Suffer:

Obesity in pets mirrors that of humans, as do the reasons — decreased physical activity, age, and an increased caloric intake, even genetic predisposition. Like humans, there are also many health problems associated with being obese, such as diabetes mellitus.