Detecting Natural Selection in the Human Genome

This paper is rather timely considering I just finished reviewing methods for detecting natural selection. Jonathan Pritchard's group has scanned SNP data from three populations (Europeans, East Asians, and Nigerians) for signatures of positive natural selection. The authors used measures of polymorphism to detect natural selection. In their approach, they polarized polymorphic SNPs as ancestral and derived (kind of like a Fay and Wu test) using the other populations as outgroups. In this type of test, high frequency derived SNPs are a hallmark of recent positive selection; the authors also argue that high frequency ancestral SNPs that are at low frequency in the other populations are also probably linked to sites under selection. They also did some simulations to show that most of the signatures of selection are not due to false positives.

(Via Anthropology.net.)