A Blog Around The Clock

Testosterone Turns Male Junco Birds Into Blustery Hunks — And Bad Dads:

The ability to ramp up testosterone production appears to drive male dark-eyed juncos to find and win mates, but it comes with an evolutionary cost. Big fluctuations in testosterone may also cause males to lose interest in parenting their own young, scientists have learned.

Blind To Beauty: How And Where Do We Process Attractiveness?:

Beauty may be in the eye of the beholder, but according to research conducted by a UBC medical student, eye candy fails to find a sweet tooth in patients with a rare disorder.

After Drought, Diversity Dries Up And Ponds All Look The Same:

An ecologist at Washington University in St. Louis has discovered that after ponds dry up through drought in a region, when they revive, the community of species in each pond tends to be very similar to one another, like so many suburban houses made of ticky tacky.

A Gene Divided Reveals The Details Of Natural Selection:

In a molecular tour de force, researchers at the University of Wisconsin-Madison have provided an exquisitely detailed picture of natural selection as it occurs at the genetic level.

Monday – the day for checking in PLoS Biology and PLoS Medicine for the newest published articles. And there is some good stuff:
Characterization of Sleep in Zebrafish and Insomnia in Hypocretin Receptor Mutants

Sleep disorders are common and poorly understood. Further, how and why the brain generates sleep is the object of intense speculations. In this study, we demonstrate that a bony fish used for genetic studies sleeps and that a molecule, hypocretin, involved in causing narcolepsy, is conserved. In humans, narcolepsy is a sleep disorder associated with sleepiness, abnormal dreaming, and paralysis and insomnia. We generated a mutant fish in which the hypocretin system was disrupted. Intriguingly, this fish sleep mutant does not display sleepiness or paralysis but has a 30% reduction of its sleep time at night and a 60% decrease in sleep bout length compared with non-mutant fish. We also studied the relationships between the hypocretin system and other sleep regulatory brain systems in zebrafish and found differences in expression patterns in the brain that may explain the differences in behavior. Our study illustrates how a sleep regulatory system may have evolved across vertebrate phylogeny. Zebrafish, a powerful genetic model that has the advantage of transparency to study neuronal networks in vivo, can be used to study sleep.

Also check the accompanying synopsis: Let Sleeping Zebrafish Lie: A New Model for Sleep Studies:

Although the function of sleep is hotly debated, one thing is clear–we, and most other animals, cannot do without it. In a new study, Yokogawa et al. describe how zebrafish sleep, finding both striking similarities to mammalian sleep and its regulation and intriguing differences.

Also, on the 4th birthday of PLoS Biology, a good editorial: When Is Open Access Not Open Access?

Since 2003, when PLoS Biology was launched, there has been a spectacular growth in “open-access” journals. The Directory of Open Access Journals (http://www.doaj.org/), hosted by Lund University Libraries, lists 2,816 open-access journals as this article goes to press (and probably more by the time you read this). Authors also have various “open-access” options within existing subscription journals offered by traditional publishers (e.g., Blackwell, Springer, Oxford University Press, and many others). In return for a fee to the publisher, an author’s individual article is made freely available and (sometimes) deposited in PubMed Central (PMC). But, as open access grows in prominence, so too has confusion about what open access means, particularly with regard to unrestricted use of content–which true open access allows. This confusion is being promulgated by journal publishers at the expense of authors and funding agencies wanting to support open access.

And check these two important articles on observatinal studies in epidemiology:
The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: Guidelines for Reporting Observational Studies
Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration

Humans Perceive Others’ Fear Faster Than Other Emotions:

You may not be fully dressed without a smile, but a look of horror will make a faster first impression. Vanderbilt University researchers have discovered that the brain becomes aware of fearful faces more quickly than those showing other emotions.

Pasturing Cows Convert Soil To A Source Of Methane, Potent Greenhouse Gas:

The cow as a killer of the climate: This inglorious role of our four-legged friends, peaceful in itself, is well-enough recognised, because, with their digestion, the animals produce methane, which is expelled continuously. Now, however, a team of German scientists from the Institute of Soil Ecology of the GSF – National Research Center for Environment and Health (Helmholtz Association of German Research Centres) and Czech colleagues at the Budweis Academy of Science have been able to show that bovine animals can also boost the production of this climate gas in soil.

Portable Diagnostic System For Foot-and-mouth Disease And Avian Flu Designed:

Smiths Detection is to launch a portable detection system that will enable veterinarians to carry out on-site diagnosis of animal diseases such as foot-and-mouth and avian flu. This new technology means vets will be able to diagnose diseases in livestock and birds in the field in less than 90 minutes rather than having to send samples for laboratory analysis.

Red Wine And Grape Juice Help Defend Against Food-borne Diseases, Study Suggests:

Red wine is known to have multiple health benefits. Researchers at the University of Missouri-Columbia have found that red wine may also protect humans from common food-borne diseases.

Want Antioxidants? Have You Eaten Micro-algae Lately?:

Some consumers want more than just their traditional nourishment requirements met. Micro-algae (eaten by humans in pre-Columbian America) are more than just nutritive. Spirulina microalgae could be a good source of antioxidants due to the presence of carotenoids deriving from chlorophyll, and provide bacterial growth inhibiting action because of certain fatty acids. Microalgae have turned out to be a potential alternative to the use of synthetic sources for these ingredients.

Buying And Selling Habitats To Help Wildlife:

Tradable permits are all the rage in environmental policy. They are already used internationally to reduce carbon emissions and improve air quality. A group of economists and ecologists from the UK, the Netherlands and Germany, are working together to find out whether such schemes could work for wildlife too. So far, it looks promising, but probably only for cultural landscapes like farmland.

As always on Fridays, there are new articles published in PLoS Computational Biology, PLoS Genetics and PLoS Pathogens. Look around to see what’s new. My pick for this week:
Inconsistencies in Neanderthal Genomic DNA Sequences:

One of the enduring questions in human evolution is the relationship of fossil groups, such as Neanderthals, with people alive today. Were Neanderthals direct ancestors of contemporary humans or an evolutionary side branch that eventually died out? Two recent papers describing the sequencing of Neanderthal nuclear DNA from fossil bone held promise for finally answering this question. However, the two studies came to very different conclusions regarding the ancestral role of Neanderthals. In this paper, we reanalyzed the data from the two original studies. We found that the two studies are inconsistent with each other, which implies that the data from at least one of the studies is probably incorrect. The likely culprit is contamination with modern human DNA, which we believe compromised the findings of one of the original Neanderthal DNA studies.

New Hearing Mechanism Discovered:

MIT researchers have discovered a hearing mechanism that fundamentally changes the current understanding of inner ear function. This new mechanism could help explain the ear’s remarkable ability to sense and discriminate sounds. Its discovery could eventually lead to improved systems for restoring hearing.

People Are Programmed To Love Chocolate, Study Finds:

For the first time, scientists have linked the all-too-human preference for a food — chocolate — to a specific, chemical signature that may be programmed into the metabolic system and is detectable by laboratory tests. The signature reads ‘chocolate lover’ in some people and indifference to the popular sweet in others, the researchers say.

Green Algae: The Nexus Of Plant-Animal Ancestry:

Genes of a tiny, single-celled green alga called Chlamydomonas reinhardtii may contain scores more data about the common ancestry of plants and animals than the richest paleontological dig. This work is described in an article in Science.

Frozen Sperm Worked For White Rhino:

Scientists from the Leibniz Institute for Zoo and Wildlife Research in Berlin successfully inseminated a rhino with formerly frozen sperm. This world-first artificial insemination of a white rhino with frozen rhino sperm took place in Budapest Zoo.

Spread Of Endogenous Retrovirus K Is Similar In The DNA Of Humans And Rhesus Monkeys:

According to paleontologic and molecular studies, the chimpanzee (Pan troglodytes) is the closer relative to the humans (Homo sapiens) and that both lineages had a common ancestor at 5 to 7 million years ago.

Benefits Of 80 Million Years Without Sex:

Scientists have discovered how a microscopic organism has benefited from nearly 80 million years without sex. Bdelloid rotifers are asexual organisms, meaning that they reproduce without males. Without sex, these animals lack many of the ways in which sexual animals adapt over generations to survive in their natural environment.

Herding Aphids: How ‘Farmer’ Ants Keep Control Of Their Food:

Chemicals on ants’ feet tranquilise and subdue colonies of aphids, keeping them close-by as a ready source of food, says new research. The study throws new light on the complex relationship between ants and the colonies of aphids whose sugary secretions the ants eat.

Discovery Of Retinal Cell Type Ends 40-year Search:

A research team combining high-energy physicists from the University of California, Santa Cruz, and neuroscientists from the Salk Institute in La Jolla, Calif., has discovered a type of retinal cell that may help monkeys, apes, and humans see motion.

Ticks Don’t Come Out In The Wash:

Before venturing into tick-infested territory, you used a topical repellent on exposed skin and outer clothing. When you returned, you did a body check and threw your clothes in the wash. But clean clothes may not be tick-free clothes. When he found a live lone star tick (Amblyomma americanum) on the agitator of his washing machine, Agricultural Research Service (ARS) entomologist John Carroll decided to find out how tough ticks are. So he bagged up nymphs from two species–the lone star tick and the deer tick, (Ixodes scapularis), the creature that transmits Lyme disease–and put them in the washing machine.

In Biology, Polarization Is A Good Thing:

Using a molecular cellular compass, individual cells in complex organisms know which way is up or down, in epithelial cells known as apical-basal polarity. Determining the orientation is essential for an individual cell to perform it’s designated tasks. Now it appears that the same compass also defines the direction of cells when migrating by establishing a morphological back and a front.

Tiny Crow Camera Spies On Clever Birds:

A new technique developed by Oxford University zoologists enables researchers to ‘hitch a ride’ with wild birds and witness their natural and undisturbed behaviour. The scientists developed miniaturised video cameras with integrated radio-tags that can be carried by wild, free-flying birds. Using this new ‘video-tracking’ technology, they spied on the behaviour of New Caledonian crows, a species renowned for its sophisticated use of tools, recording behaviours never seen before.

Diet With A Little Meat Uses Less Land Than Many Vegetarian Diets:

A low-fat vegetarian diet is very efficient in terms of how much land is needed to support it. But adding some dairy products and a limited amount of meat may actually increase this efficiency, Cornell researchers suggest.

Early Apes Walked Upright 15 Million Years Earlier Than Previously Thought, Evolutionary Biologist Argues:

An extraordinary advance in human origins research reveals evidence of the emergence of the upright human body plan over 15 million years earlier than most experts have believed. More dramatically, the study confirms preliminary evidence that many early hominoid apes were most likely upright bipedal walkers sharing the basic body form of modern humans.

Difference Between Fish And Humans: Century-old Developmental Question Answered:

Embryologists at UCL (University College London) have helped solve an evolutionary riddle that has been puzzling scientists for over a century. They have identified a key mechanism in the initial stages of an embryo’s development that helps differentiate more highly evolved species, including humans, from less evolved species, such as fish. The findings of the research, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), were published online by the journal Nature.

As usual on Tuesday nights, lots of cool stuff got published on PLoS ONE today. Here are some of my picks, but you should check all 30 of them (so, this week I am correct – there are now 1000+ articles on PLoS ONE):
Large-Scale Mitochondrial DNA Analysis of the Domestic Goat Reveals Six Haplogroups with High Diversity:

Studying the genetic diversity of domesticated animals can provide insights into their domestication, and even the history of human migration. In this paper Pompanon and colleagues study mitochondrial DNA diversity of the domestic goat from 2430 animals from widespread Old World geographic origins. The researchers find a very high degree of mitochondrial diversity amongst goats, but suggest that even with such a large dataset, little can be concluded about the origin of goat domestication.

The Environmental Dependence of Inbreeding Depression in a Wild Bird Population:

Evolutionary genetic theory suggests that if related individuals breed, their offspring are likely to be less “fit” (or evolutionarily successful) than outbred offspring, because of the increased chance of inheriting two copies of a harmful recessive gene. The authors of this paper analysed the interaction between environment and inbreeding on individual fitness in a population of great tits. Their results suggest that in wild populations, the interaction between inbreeding and environment on fitness may be considerable.

Wnt and TGF-β Expression in the Sponge Amphimedon queenslandica and the Origin of Metazoan Embryonic Patterning:

The origin of metazoan development and differentiation was contingent upon the evolution of cell adhesion, communication and cooperation mechanisms. While components of many of the major cell signalling pathways have been identified in a range of sponges (phylum Porifera), their roles in development have not been investigated and remain largely unknown. Here, we take the first steps toward reconstructing the developmental signalling systems used in the last common ancestor to living sponges and eumetazoans by studying the expression of genes encoding Wnt and TGF-β signalling ligands during the embryonic development of a sponge.
Using resources generated in the recent sponge Amphimedon queenslandica (Demospongiae) genome project, we have recovered genes encoding Wnt and TGF-β signalling ligands that are critical in patterning metazoan embryos. Both genes are expressed from the earliest stages of Amphimedon embryonic development in highly dynamic patterns. At the time when the Amphimedon embryos begin to display anterior-posterior polarity, Wnt expression becomes localised to the posterior pole and this expression continues until the swimming larva stage. In contrast, TGF-β expression is highest at the anterior pole. As in complex animals, sponge Wnt and TGF-β expression patterns intersect later in development during the patterning of a sub-community of cells that form a simple tissue-like structure, the pigment ring. Throughout development, Wnt and TGF-β are expressed radially along the anterior-posterior axis.
We infer from the expression of Wnt and TGF-β in Amphimedon that the ancestor that gave rise to sponges, cnidarians and bilaterians had already evolved the capacity to direct the formation of relatively sophisticated body plans, with axes and tissues. The radially symmetrical expression patterns of Wnt and TGF-β along the anterior-posterior axis of sponge embryos and larvae suggest that these signalling pathways contributed to establishing axial polarity in the very first metazoans.

Maladaptation and the Paradox of Robustness in Evolution:

Organisms use a variety of mechanisms to protect themselves against perturbations. For example, repair mechanisms fix damage, feedback loops keep homeostatic systems at their setpoints, and biochemical filters distinguish signal from noise. Such buffering mechanisms are often discussed in terms of robustness, which may be measured by reduced sensitivity of performance to perturbations.
I use a mathematical model to analyze the evolutionary dynamics of robustness in order to understand aspects of organismal design by natural selection. I focus on two characters: one character performs an adaptive task; the other character buffers the performance of the first character against perturbations. Increased perturbations favor enhanced buffering and robustness, which in turn decreases sensitivity and reduces the intensity of natural selection on the adaptive character. Reduced selective pressure on the adaptive character often leads to a less costly, lower performance trait.
The paradox of robustness arises from evolutionary dynamics: enhanced robustness causes an evolutionary reduction in the adaptive performance of the target character, leading to a degree of maladaptation compared to what could be achieved by natural selection in the absence of robustness mechanisms. Over evolutionary time, buffering traits may become layered on top of each other, while the underlying adaptive traits become replaced by cheaper, lower performance components. The paradox of robustness has widespread implications for understanding organismal design.

Homeotic Evolution in the Mammalia: Diversification of Therian Axial Seriation and the Morphogenetic Basis of Human Origins:

Despite the rising interest in homeotic genes, little has been known about the course and pattern of evolution of homeotic traits across the mammalian radiation. An array of emerging and diversifying homeotic gradients revealed by this study appear to generate new body plans and drive evolution at a large scale.
This study identifies and evaluates a set of homeotic gradients across 250 extant and fossil mammalian species and their antecedents over a period of 220 million years. These traits are generally expressed as co-linear gradients along the body axis rather than as distinct segmental identities. Relative position or occurrence sequence vary independently and are subject to polarity reversal and mirroring. Five major gradient modification sets are identified: (1)-quantitative changes of primary segmental identity pattern that appeared at the origin of the tetrapods ; (2)-frame shift relation of costal and vertebral identity which diversifies from the time of amniote origins; (3)-duplication, mirroring, splitting and diversification of the neomorphic laminar process first commencing at the dawn of mammals; (4)-emergence of homologically variable lumbar lateral processes upon commencement of the radiation of therian mammals and ; (5)-inflexions and transpositions of the relative position of the horizontal septum of the body and the neuraxis at the emergence of various orders of therian mammals. Convergent functional changes under homeotic control include laminar articular engagement with septo-neural transposition and ventrally arrayed lumbar transverse process support systems.
Clusters of homeotic transformations mark the emergence point of mammals in the Triassic and the radiation of therians in the Cretaceous. A cluster of homeotic changes in the Miocene hominoid Morotopithecus that are still seen in humans supports establishment of a new “hominiform” clade and suggests a homeotic origin for the human upright body plan.

Nullomers: Really a Matter of Natural Selection?:

Nullomers are short DNA sequences that are absent from the genomes of humans and other species. Assuming that nullomers are the signatures of natural selection against deleterious sequences in humans, the use of nullomers in drug target identification, pesticide development, environmental monitoring, and forensic applications has been envisioned.
Here, we show that the hypermutability of CpG dinucleotides, rather than the natural selection against the nullomer sequences, is likely the reason for the phenomenal event of short sequence motifs becoming nullomers. Furthermore, many reported human nullomers differ by only one nucleotide, which reinforces the role of mutation in the evolution of the constellation of nullomers in populations and species. The known nullomers in chimpanzee, cow, dog, and mouse genomes show patterns that are consistent with those seen in humans.
The role of mutations, instead of selection, in generating nullomers cast doubt on the utility of nullomers in many envisioned applications, because of their dependence on the role of lethal selection on the origin of nullomers.

Demographic Histories of ERV-K in Humans, Chimpanzees and Rhesus Monkeys:

We detected 19 complete endogenous retroviruses of the K family in the genome of rhesus monkey (Macaca mulatta; RhERV-K) and 12 full length elements in the genome of the common chimpanzee (Pan troglodytes; CERV-K). These sequences were compared with 55 human HERV-K and 20 CERV-K reported previously, producing a total data set of 106 full-length ERV-K genomes. Overall, 61% of the human elements compared to 21% of the chimpanzee and 47% of rhesus elements had estimated integration times less than 4.5 million years before present (MYBP), with an average integration times of 7.8 MYBP, 13.4 MYBP and 10.3 MYBP for HERV-K, CERV-K and RhERV-K, respectively. By excluding those ERV-K sequences generated by chromosomal duplication, we used 63 of the 106 elements to compare the population dynamics of ERV-K among species. This analysis indicated that both HERV-K and RhERV-K had similar demographic histories, including markedly smaller effective population sizes, compared to CERV-K. We propose that these differing ERV-K dynamics reflect underlying differences in the evolutionary ecology of the host species, such that host ecology and demography represent important determinants of ERV-K dynamics.

SIRNA-Directed In Vivo Silencing of Androgen Receptor Inhibits the Growth of Castration-Resistant Prostate Carcinomas:

Prostate carcinomas are initially dependent on androgens, and castration or androgen antagonists inhibit their growth. After some time though, tumors become resistant and recur with a poor prognosis. The majority of resistant tumors still expresses a functional androgen receptor (AR), frequently amplified or mutated.
To test the hypothesis that AR is not only expressed, but is still a key therapeutic target in advanced carcinomas, we injected siRNA targeting AR into mice bearing exponentially growing castration-resistant tumors. Quantification of siRNA into tumors and mouse tissues demonstrated their efficient uptake. This uptake silenced AR in the prostate, testes and tumors. AR silencing in tumors strongly inhibited their growth, and importantly, also markedly repressed the VEGF production and angiogenesis.
Our results demonstrate that carcinomas resistant to hormonal manipulations still depend on the expression of the androgen receptor for their development in vivo. The siRNA-directed silencing of AR, which allows targeting overexpressed as well as mutated isoforms, triggers a strong antitumoral and antiangiogenic effect. siRNA-directed silencing of this key gene in advanced and resistant prostate tumors opens promising new therapeutic perspectives and tools.

Implementing Routine HIV Testing: The Role of State Law:

In September 2006, the Centers for Disease Control and Prevention (CDC) recommended routine HIV testing for all Americans aged 13-64, which would eliminate requirements for written consent and pretest counseling as previously required. However, this approach may conflict with state requirements concerning pretest counseling and informed consent for HIV testing. Our survey of state HIV testing laws demonstrates that the majority of states have HIV testing requirements that are inconsistent with the CDC’s recommendations. Moreover, states that have recently amended their laws have not eased the requirements for pretest counseling and informed consent. The reasons for the persistence of these legal requirements must be understood to effect policy changes to increase HIV testing.

Moderate Neonatal Stress Decreases Within-Group Variation in Behavioral, Immune and HPA Responses in Adult Mice:

The significance of behavioral neuroscience and the validity of its animal models of human pathology largely depend on the possibility to replicate a given finding across different laboratories. Under the present test and housing conditions, this axiom fails to resist the challenge of experimental validation. When several mouse strains are tested on highly standardized behavioral test batteries in different laboratories, significant strain×lab interactions are often detected. This limitation, predominantly due to elevated within-group variability observed in control subjects, increases the number of animals needed to address fine experimental questions. Laboratory rodents display abnormal stress and fear reactions to experimental testing, which might depend on the discrepancy between the stability of the neonatal environment and the challenging nature of the adult test and housing conditions.
Stimulating neonatal environments (e.g. brief maternal separations, increased foraging demands or maternal corticosterone supplementation) reduce stress and fear responses in adulthood. Here we tested whether reduced fearfulness associated with experimental testing would also reduce inter-individual variation. In line with our predictions, we show that a moderate elevation in neonatal corticosterone through maternal milk significantly reduces fear responses and inter-individual variability (average 44%) in adult mouse offspring.
We observed reduced variation in pain perception, novelty preference, hormonal stress response and resistance to pathogen infection. This suggests that the results of this study may apply to a relatively broad spectrum of neuro-behavioral domains. Present findings encourage a reconsideration of the basic principles of neonatal housing systems to improve the validity of experimental models and reduce the number of animals used.

Adaptive Evolution of a Stress Response Protein:

Some cancers are mediated by an interplay between tissue damage, pathogens and localised innate immune responses, but the mechanisms that underlie these linkages are only beginning to be unravelled.
Here we identify a strong signature of adaptive evolution on the DNA sequence of the mammalian stress response gene SEP53, a member of the epidermal differentiation complex fused-gene family known for its role in suppressing cancers. The SEP53 gene appears to have been subject to adaptive evolution of a type that is commonly (though not exclusively) associated with coevolutionary arms races. A similar pattern of molecular evolution was not evident in the p53 cancer-suppressing gene.
Our data thus raises the possibility that SEP53 is a component of the mucosal/epithelial innate immune response engaged in an ongoing interaction with a pathogen. Although the pathogenic stress mediating adaptive evolution of SEP53 is not known, there are a number of well-known candidates, in particular viruses with established links to carcinoma.

Habitat Fragmentation, Variable Edge Effects, and the Landscape-Divergence Hypothesis:

Edge effects are major drivers of change in many fragmented landscapes, but are often highly variable in space and time. Here we assess variability in edge effects altering Amazon forest dynamics, plant community composition, invading species, and carbon storage, in the world’s largest and longest-running experimental study of habitat fragmentation. Despite detailed knowledge of local landscape conditions, spatial variability in edge effects was only partially foreseeable: relatively predictable effects were caused by the differing proximity of plots to forest edge and varying matrix vegetation, but windstorms generated much random variability. Temporal variability in edge phenomena was also only partially predictable: forest dynamics varied somewhat with fragment age, but also fluctuated markedly over time, evidently because of sporadic droughts and windstorms. Given the acute sensitivity of habitat fragments to local landscape and weather dynamics, we predict that fragments within the same landscape will tend to converge in species composition, whereas those in different landscapes will diverge in composition. This ‘landscape-divergence hypothesis’, if generally valid, will have key implications for biodiversity-conservation strategies and for understanding the dynamics of fragmented ecosystems.

As always, look around, read the articles, rate them, post comments and annotations, send trackbacks if you blog about them, and if you want to do a Journal Club on one of them, let me know.

A newspaper should hire me to be that guy whose only job is to write titles and headlines. I can make them as misleading and sensationalist as the best of ’em!
But really, this year’s Nobel Prize for Physics is going to Albert Fert and Peter Grunberg for the invention of Giant Magnetoresistance. And yes, one of the many thingamajigs that uses this technology is iPod. But it makes for such a cool headline….

Why Are Huge Numbers Of Camels Dying In Africa And Saudi Arabia?:

More than 2000 dromedaries — Arabian camels — have died since August 10 in Saudi Arabia. Various theories have been put forward to explain the numerous deaths. For several years, the Sahel and the Horn of Africa have also seen similar numbers of deaths. In 1995-1996, CIRAD worked on a fatal epizootic disease affecting dromedaries in Ethiopia.

Humans Unknowing Midwives For Pregnant Moose:

When it’s time for moose to give birth in the Greater Yellowstone Ecosystem, they head to where it is safest from predators — namely closer to people, according to a new study by the Wildlife Conservation Society. Published in the Royal Society’s journal Biology Letters, the study says that moose avoid predation of their calves by grizzly bears by moving closer to roads and other infrastructure prior to giving birth.

Ancient African Megadroughts May Have Driven Human Evolution — Out Of Africa:

From 135,000 to 90,000 years ago tropical Africa had megadroughts more extreme and widespread than any previously known for that region, according to new research.

Chronic Arguing With Your Spouse May Raise Your Heart Disease Risk:

Individuals whose close relationships have negative aspects, such as conflict and adverse exchanges, appear to have an increased risk of heart disease than those with more positive close relationships, according to a new report.