Wednesday, June 07, 2017

Hair Between Their Eyes

Steve Hsu leads us to a new paper which finds evidence of recent selection for the polygenic traits height, educational attainment, and "self reported unibrow." Steve is particularly interested in the evidence for selection for genes associated (with educational attainment in Europeans) in East Asians. That selection appears to have occurred during the past 10,000 years.

Although the paper is about 84 pages, most of that is figures and tables, with only about 19 pages of exposition. I found it more understandable than Steve's very brief summary.

It's probably obvious that selection is important for polygenic traits, since most significant differences are polygenic, but data to date has been sparse.

From the abstract:

An open question in human evolution is the importance of polygenic adaptation: adaptive changes in the mean of a multifactorial trait due to shifts in allele frequencies across many loci. In recent years, several methods have been developed to detect polygenic adaptation using loci identified in genome-wide association studies (GWAS). Though powerful, these methods suffer from limited interpretability: they can detect which sets of populations have evidence for polygenic adaptation, but are unable to reveal where in the history of multiple populations these processes occurred. To address this, we created a method to detect polygenic adaptation in an admixture graph, which is a representation of the historical divergences and admixture events relating different populations through time.