Afarensis

There are some interesting pieces of research out there this week.

Science Daily mentions long term research, published in Current Directions in Psychological Science, on tool use by Japanese macaques:

The scientists found, for example, that an infant's proximity to their mother had a significant impact on the development of the infant's stone-handling abilities. In other words, infants with mothers who frequently exhibited stone-handling behaviors spent more time with their mother, about 75% of their time, during the first three months of life, and they also participated in stone-handling earlier in life than the other infants. These findings suggest that the mothers' frequent stone-handling caught the infants' attention, and as a result, the infants acquired the behavior more quickly than other infants.

PLoS Genetics has an interesting paper called "Contrasting Mode of Evolution at a Coat Color Locus in Wild and Domestic Pigs". Here is the abstract:

Despite having only begun ~10,000 years ago, the process of domestication has resulted in a degree of phenotypic variation within individual species normally associated with much deeper evolutionary time scales. Though many variable traits found in domestic animals are the result of relatively recent human-mediated selection, uncertainty remains as to whether the modern ubiquity of long-standing variable traits such as coat color results from selection or drift, and whether the underlying alleles were present in the wild ancestor or appeared after domestication began. Here, through an investigation of sequence diversity at the porcine melanocortin receptor 1 (MC1R) locus, we provide evidence that wild and domestic pig (Sus scrofa) haplotypes from China and Europe are the result of strikingly different selection pressures, and that coat color variation is the result of intentional selection for alleles that appeared after the advent of domestication. Asian and European wild boar (evolutionarily distinct subspecies) differed only by synonymous substitutions, demonstrating that camouflage coat color is maintained by purifying selection. In domestic pigs, however, each of nine unique mutations altered the amino acid sequence thus generating coat color diversity. Most domestic MC1R alleles differed by more than one mutation from the wild-type, implying a long history of strong positive selection for coat color variants, during which time humans have cherry-picked rare mutations that would be quickly eliminated in wild contexts. This pattern demonstrates that coat color phenotypes result from direct human selection and not via a simple relaxation of natural selective pressures.

BMC Evolutionary Biology has a paper that reports on research into Neanderthal ABO blood groups. From the conclusion:

These results suggest that the genetic change responsible for the O blood group in humans predates the human and Neandertal divergence. A potential selective event associated with the emergence of the O allele may have therefore occurred after humans separated from their common ancestor with chimpanzees and before the human-Neandertal population divergence.

Also from BMC Evolutionary Biology is an interesting article Signatures of selection in natural populations adapted to chronic pollution. Here is the abstract:

Populations of the teleost fish Fundulus heteroclitus appear to flourish in heavily polluted and geographically separated Superfund sites. Populations from three Superfund sites (New Bedford Harbor, MA, Newark Bay, NJ, and Elizabeth River, VA) have independently evolved adaptive resistance to chemical pollutants. In these polluted populations, natural selection likely has altered allele frequencies of loci that affect fitness or that are linked to these loci. The aim of this study was to identify loci that exhibit non-neutral behavior in the F. heteroclitus genome in polluted populations versus clean reference populations.

BMC Evolutionary Biology also has an interesting paper on bears. Mitochondrial genomes reveal an explosive radiation of extinct and extant bears near the Miocene-Pliocene boundary:

Sequences from extinct bears represent the third and fourth Pleistocene species for which complete mitochondrial genomes have been sequenced. Moreover, the cave bear specimen demonstrates that mitogenomic studies can be applied to Pleistocene fossils that have not been preserved in permafrost, and therefore have a broad application within ancient DNA research. Molecular dating of the mtDNA divergence times suggests a rapid radiation of bears in both the Old and New Worlds around 5 million years ago, at the Miocene-Pliocene boundary. This coincides with major global changes, such as the Messinian crisis and the first opening of the Bering Strait, and suggests a global influence of such events on species radiations.

Finally, Science Daily reports on research - supposed to be in BMC Evolutionary Biology - into the evolutionary causes of some common birth disorders:

These clinical insights were gleaned from work demonstrating that certain portions of the Msx proteins have remained constant over extremely long periods of time (>600 million years) while other Msx protein modules had duplicated and then subsequently diverged within the duplicated Msx sister genes, a previously unrecognized avenue for the evolution of morphological innovation. These observations will help to prioritize future clinical and functional research on these disease mutations. An outgrowth of these insights was the realization that the highly conserved protein modules that make up the Msx protein help to define a class of animal specific master control genes that each go on to specifically pattern the body plan of all modern animals.