A Blog Around The Clock

Understanding Smooth Eye Pursuit: The Incredible Targeting System Of Human Vision:

Researchers at the University of Pennsylvania have shed new light on how the brain and eye team up to spot an object in motion and follow it, a classic question of human motor control. The study shows that two distinctly different ways of seeing motion are used – one to catch up to a moving object with our eyes, a second to lock on and examine it.

Wolves Of Alaska Became Extinct 12,000 Years Ago, Scientists Report:

The ancient gray wolves of Alaska became extinct some 12,000 years ago, and the wolves in Alaska today are not their descendents but a different subspecies, an international team of scientists reports in the July 3 print edition of the journal Current Biology.

Reap What Your Ancestors Sowed: Cheating Has Long-term Consequences In Evolution Of Cooperation:

Freeloaders can live on the fruits of the cooperation of others, but their selfishness can have long-term consequences, reports an evolutionary biologist from The University of Texas at Austin in a new study.

Altruistic Rats: First Evidence For Generalized Reciprocal Cooperation In Non-humans:

Cooperation in animals has long been a major focus in evolutionary biology. In particular, reciprocal altruism, where helpful acts are contingent upon the likelihood of getting help in return, is especially intriguing because it is open to cheaters. In a new study published this week in the open-access journal PLoS Biology, Claudia Rutte and Michael Taborsky demonstrate the first evidence for generalized reciprocal cooperation in non-humans. The authors show that rats who received help in the past were more likely to help another unknown partner.

Mother-of-pearl: Classic Beauty And Remarkable Strength:

While the shiny material of pearls and abalone shells has long been prized for its iridescence and aesthetic value in jewelry and decorations, scientists admire mother-of-pearl for other physical properties as well.

Stressed-out African Naked Mole-rats May Provide Clues About Human Infertility:

A tiny, blind, hairless subterranean rodent that lives in social colonies in the harsh, semi-arid conditions of Africa could shed light on stress-related infertility in humans, the 23rd annual meeting of the European Society of Human Reproduction and Embryology will hear.

Glimmer Of Hope For Tahitian Tree Snails’ Survival:

Despite the mass extermination of Tahiti’s unique species of tree snails in recent decades, much of their original genetic diversity can still be found in remnant populations that survive on the island, researchers report in the July 3rd issue of Current Biology, a Cell Press publication. The findings offer renewed hope that targeted conservation measures may yet preserve a representative, although impoverished, fraction of Tahiti’s endemic tree snail genetic diversity in the wild–a feat earlier believed to be impossible.

Jellyfish Population Explosion Leads To New Use For Waste Creatures:

Amid growing concern about how to dispose of a booming population of jellyfish — including 6-foot-long monsters weighing more than 400 pounds — scientists in Japan are reporting development of a process for extracting a commercially-valuable biomaterial from the marine animals. Their report is scheduled for the July 27 issue of ACS’ Journal of Natural Products, a monthly publication.

Advancing Research On Interplay Between Biology And Society:

Scientists will find new ways of understanding the interactions of the biological sciences with society, as a result of awards from the National Science Foundation’s (NSF) directorates for biological sciences and for social, behavioral, and economic sciences.

A bunch of papers just went live on PLoS-ONE and, after a quick scan, these three papers caught my eye:
The Durability of Public Goods Changes the Dynamics and Nature of Social Dilemmas:

An implicit assumption underpins basic models of the evolution of cooperation, mutualism and altruism: The benefits (or pay-offs) of cooperation and defection are defined by the current frequency or distribution of cooperators. In social dilemmas involving durable public goods (group resources that can persist in the environment-ubiquitous from microbes to humans) this assumption is violated. Here, we examine the consequences of relaxing this assumption, allowing pay-offs to depend on both current and past numbers of cooperators. We explicitly trace the dynamic of a public good created by cooperators, and define pay-offs in terms of the current public good. By raising the importance of cooperative history in determining the current fate of cooperators, durable public goods cause novel dynamics (e.g., transient increases in cooperation in Prisoner’s Dilemmas, oscillations in Snowdrift Games, or shifts in invasion thresholds in Stag-hunt Games), while changes in durability can transform one game into another, by moving invasion thresholds for cooperation or conditions for coexistence with defectors. This enlarged view challenges our understanding of social cheats. For instance, groups of cooperators can do worse than groups of defectors, if they inherit fewer public goods, while a rise in defectors no longer entails a loss of social benefits, at least not in the present moment (as highlighted by concerns over environmental lags). Wherever durable public goods have yet to reach a steady state (for instance due to external perturbations), the history of cooperation will define the ongoing dynamics of cooperators.

Leveraging Hierarchical Population Structure in Discrete Association Studies:

Population structure can confound the identification of correlations in biological data. Such confounding has been recognized in multiple biological disciplines, resulting in a disparate collection of proposed solutions. We examine several methods that correct for confounding on discrete data with hierarchical population structure and identify two distinct confounding processes, which we call coevolution and conditional influence. We describe these processes in terms of generative models and show that these generative models can be used to correct for the confounding effects. Finally, we apply the models to three applications: identification of escape mutations in HIV-1 in response to specific HLA-mediated immune pressure, prediction of coevolving residues in an HIV-1 peptide, and a search for genotypes that are associated with bacterial resistance traits in Arabidopsis thaliana. We show that coevolution is a better description of confounding in some applications and conditional influence is better in others. That is, we show that no single method is best for addressing all forms of confounding. Analysis tools based on these models are available on the internet as both web based applications and downloadable source code at http://atom.research.microsoft.com/bio/phylod.aspx.

Super-Genotype: Global Monoclonality Defies the Odds of Nature:

The ability to respond to natural selection under novel conditions is critical for the establishment and persistence of introduced alien species and their ability to become invasive. Here we correlated neutral and quantitative genetic diversity of the weed Pennisetum setaceum Forsk. Chiov. (Poaceae) with differing global (North American and African) patterns of invasiveness and compared this diversity to native range populations. Numerous molecular markers indicate complete monoclonality within and among all of these areas (FST = 0.0) and is supported by extreme low quantitative trait variance (QST = 0.00065-0.00952). The results support the general-purpose-genotype hypothesis that can tolerate all environmental variation. However, a single global genotype and widespread invasiveness under numerous environmental conditions suggests a super-genotype. The super-genotype described here likely evolved high levels of plasticity in response to fluctuating environmental conditions during the Early to Mid Holocene. During the Late Holocene, when environmental conditions were predominantly constant but extremely inclement, strong selection resulted in only a few surviving genotypes.

Wood Ant Queen Has No Egg-laying Monopoly:

The reproductive monopoly of the ant queen is not as strong as is often thought. Dr. Heikki Helanterä and Prof. Lotta Sundström, biologists working at the University of Helsinki, Finland, investigated worker ovary development and egg laying in nine Northern European wood ant species of the genus Formica, and revealed wide spread reproductive endeavours by workers.

City Site Was Dinosaur Dining Room:

A dinosaur bone bed in southwest Edmonton that served as a feeding area for the direct ancestor of Tyrannosaurus rex has revealed that two dinosaurs, thought to have lived in different eras, actually lived at the same time. Scientists digging for bones at the site this year discovered fossils of Edmontosaurus and Saurolophus this year.

Translating Form Into Function:

In the last 40 years, scientists have perfected ways to determine the knot-like structure of enzymes, but they’ve been stumped trying to translate the structure into an understanding of function — what the enzyme actually does in the body. This puzzle has hindered drug discovery, since many of the most successful drugs work by blocking enzyme action. Now, in an expedited article in Nature, researchers show that a solution to the puzzle is finally in sight.

Scientists Find Endangered Grey-shanked Doucs In Vietnam:

A team of scientists from WWF and Conservation International (CI) has discovered the world’s largest known population of grey-shanked doucs (Pygathrix cinerea), increasing chances that the Endangered monkey can be saved from extinction.