HENRY

Eureka Alert says:

Researchers believe they have solved a mystery that has puzzled evolutionary scientists for years… if ‘good’ genes spread through the population, why are individuals so different?

…and the answer to this lek paradox is in a paper published in the latest Heredity, Sexual selection and the evolution of evolvability :

Here we show that sexual selection can have an effect on the rate of mutation. We simulated the fate of a genetic modifier of the mutation rate in a sexual population with and without sexual selection (modelled using a female choice mechanism). Female choice for ‘good genes’ should reduce variability among male subjects, leaving insufficient differences to maintain female preferences. However, female choice can actually increase genetic variability by supporting a higher mutation rate in sexually selected traits. Increasing the mutation rate will be selected against because of the resulting decline in mean fitness. However, it also increases the probability of rare beneficial mutations arising, and mating skew caused by female preferences for male subjects carrying those beneficials with few deleterious mutations (‘good genes’) can lead to a mutation rate above that expected under natural selection. A choice of two male subjects was sufficient for there to be a twofold increase in the mutation rate as opposed to a decrease found under random mating.

There’s a fascinating paper in Proceedings of the Royal Society demonstrating that a number of bird species in Chernobyl prefer to nest in areas with low radioactivity:

(the) Great tit Parus major and pied flycatcher Ficedula hypoleuca significantly avoided nest boxes in heavily contaminated areas, with a stronger effect in flycatchers than in tits. These preferences could not be attributed to variation in habitat quality or resource abundance, as determined by analyses of habitat use and the relationship between radiation and life-history characters. Likewise, none of these effects could be attributed to individuals of a specific age breeding in the most contaminated areas. (…) We suggest that individual body condition rather than secondary effects of radiation on resource abundance account for the effects on nest box use and hatching success.

The full paper is here and The New Scientist also has coverage

Another criticism of the “out-of-Africa” scenario for human ancestry in today’s Molecular Biology and Evolution:

Previous studies have found that at most human loci, ancestral alleles are “African,” in the sense that they reach their highest frequency there. Conventional wisdom holds that this reflects a recent African origin of modern humans.

This paper challenges that view by showing that the empirical pattern (of elevated allele frequencies within Africa) is not as pervasive as has been thought. We confirm this African bias in a set of mainly protein-coding loci, but find a smaller bias in Alu insertion polymorphisms, and an even smaller bias in noncoding loci. Thus, the strong bias that was originally observed must reflect some factor that varies among data sets—something other than population history. This factor may be the per-locus mutation rate: the African bias is most pronounced in loci where this rate is high.

Abstract at MBE Online

Today’s finest selection from the wiki: Resistentialism:

Resistentialism is a theory in which inanimate objects display hostile desires towards human beings. For example, objects that cause problems (like lost keys or a fleeing bouncy ball) exhibit a high degree of resistentialism. In other words, a war is being fought between humans and inanimate objects, and all the little annoyances objects give people throughout the day are battles between the two.

It’s 5 a.m., and I’ve had 3 hours sleep, so this is appropriate:

…what, exactly, is sleep for? A little more than a half-century ago, most scientists believed that sleep was an inactive state, a kind of parenthesis in living. Then in 1951, Eugene Aserinsky, a clever graduate student at the University of Chicago, hooked his son Armond to a retooled “brain wave machine” and monitored the boy’s sleep deep into the night. Aserinsky observed sharp spikes of activity on his readout, suggesting that Armond’s eyes were darting back and forth. This turned out to reflect the distinctive state within sleep dubbed rapid eye movement, or REM— a “new continent in the brain,” as a colleague later put it.

Find out in Our obsession with sleep at Slate Magazine.

Careful with your programming, folks:

One of the most spectacular flameouts in science happened last year. In a short letter (barely over 300 words long) published in Science in the very last issue of 2006, Geoffrey Chang, a crystallographer, retracted 3 Science articles, a Nature article, a PNAS article and a JMB article. The sum of 5 years of work was destroyed, apparently, over a single sign error in a data-processing program.

Continue reading A Sign, a Flipped Structure, and a Scientific Flameout of Epic Proportions

Recent reports are suggesting that the Orang-utan may be extinct within 5 years as their habitats are vanishing faster than predicted. Read more at The Guardian