FDA orders 23andMe to cease marketing

On November 22nd the FDA issued an order for the genetics company 23andMe to immediately cease marketing for their home DNA screening kits after several warnings about "misleading claims." The FDA argues that the company "has not analytically or clinically validated the personal genome service for its intended uses." The original FDA letter can be found here, and a CNN article can be found here. 

Ancient Siberian genome publication out in Nature

The 42,000 year old genome of the Siberian child earlier announced in Science News is now officially published in this week's Nature. When compared with various living human groups, researchers found the individual to be most closely related to Native Americans, but also that a portion of the genome was most closely related to western Europeans. This week's Nature Podcast features an interview with the lead author.

Genetic Adaptation Potluck: Climate

This article published in Plos Genetics focuses on genetic variation due to climate pressures. The researchers used a bioinformatics approach to genotype 873 SNPs in genes involved in energy metabolism across 54 worldwide populations. They found the strongest signals in LEPR R109K, FABP2 A54T, genes that are known to be involved with cold intolerance. Thus, overall this study suggests that climate has been one of many important selective pressures affecting genes implicated in metabolism.

Proceedings of Royal Society B, December 22, 2013

In the most recent issue of Proceedings of Royal Society B, one article was particularly relevant to molecular anthropology.  The paper titled "Chimpanzee fauna isotopes provide new interpretations of fossil ape and hominin ecologies" examined the isotopic composition of oxygen and carbon in the tooth enamel of modern and ancient hominin species including Ardipithicus and  Sivapithicus.  The study found that Sivapithicus, a Miocine ape, likely lived in area with canopy, similar to modern chimpanzees, though fed relatively more on leaves.  In contrast, Ardipithicus was found to feed on arboreal and terrestrial sources in a habitat that was predicted to have more open spaces than that of modern chimpanzees. The author, Sherry V. Nelson, hopes to apply this technique to a wide range of fossil specimens to gain a better understanding of diet and habitat in ancient anthropoid species.

How A Gene For Fair Skin Spread Across India

http://www.popsci.com/article/science/how-gene-fair-skin-spread-across-india

This article discusses a recent paper examining genes for skin color in India.  Before this study, work on skin color genes had not included large samples from South Asia, but instead had focused on Europe and East Asia.  The team found that the gene that is mostly responsible for light skin color in Indian populations is SLC24A5, the gene that also causes fair coloring in European populations as well.  This is in contrast to a set of genes that are responsible for skin pigmentation in East Asia.  The researchers also found that while normally the distribution of light skin color alleles aries latitudinally in areas, for example in Europe its spread seems to be entirely determined by evolution, in India the pattern is much more closely linked to population movements and history.

Human Adaptation Potluck: Hunter-Gatherer Specific Adaptation

Lachance et al. (2012) sequenced whole genomes of one individual each from three African hunter-gatherer groups: Cameroonian Pygmies, the Hadza, and the Sandawe. Many of the findings of this study were discussed by Dr. Sarah Tishkoff (Penn) in a very interesting lecture given at EEB last week, including the discovery of >3 million novel SNPs (unknown on dbSNP & 1000 Genomes) and evidence for archaic admixture in all three populations.

In terms of adaptation, all three populations showed evidence for local environment-specific selection. Regions of divergence in all three groups were enriched for genes involved in immune system and sensory (smell and taste) function. Particularly interesting, regions showing signatures of selection in the pygmies encompassed genes active in pituitary and reproductive function. This finding suggests that pituitary activity in development may be related to the short-stature pygmy phenotype.

Better Review Article for Recent Human Adaptation

A review article recently published in Nature offers a good overview on the methods, cautions, and recent advancements in studying Recent Human Adaptations. The article touches on methods to account for false-positives in WGS and SNP frequency studies and calls for more attention to intergenic regions of the genome. It also highlights current adaptive genes and pathways, such as those relating to skin pigmentation, altitude, lactase persistence, and type II diabetes.

The original article can be found here: http://www.nature.com/nrg/journal/v14/n10/full/nrg3604.html