In this track, the value shown for each SNP is -log10 of the
fraction of SNPs with a more extreme FST value than that SNP.
(also known as the Fixation index) values were calculated
from SNPs genotyped in 53 populations worldwide by the
Genome Diversity Project in collaboration with the
du Polymorphisme Humain (HGDP-CEPH).
This track and several others are available from the
HGDP Selection Browser.
Fixation index (FST) is a measure of population differentiation based
on genetic polymorphism data, such as Single nucleotide polymorphisms
(SNPs) or microsatellites. It is a special case of
concept developed in the 1920s by Sewall Wright. This statistic
compares the genetic variability within and between populations and is
frequently used in the field of population genetics.
FST is the proportion of the total genetic variance
contained in a subpopulation (the S subscript) relative to the total
genetic variance (the T subscript). Values can range from 0 to 1. High
FST implies a considerable degree of differentiation among
Samples collected by the HGDP-CEPH from 1,043 individuals from around the
world were genotyped for 657,000 SNPs at
The 53 populations were divided into seven continental groups: Africa,
Middle East, Europe, South Asia, East Asia, Oceania and the Americas.
FST was computed for all SNPs, and then each SNP's place in
the empirical FST distribution was used to derive the scores
shown in this track, -log10 of the fraction of SNPs with a
more extreme FST value than that SNP.
Thanks to the HGDP-CEPH and Joe Pickrell in the
lab at the University of Chicago for providing these data.
Pickrell JK, Coop G, Novembre J, Kudaravalli S, Li J, Absher D,
Srinivasan BS, Barsh GS, Myers RM, Feldman MW, Pritchard JK.
Signals of recent positive selection in a worldwide sample of
human populations. Genome Res. 2009 May;19(5):826-37.
Li JZ, Absher DM, Tang H, Southwick AM, Casto AM, Ramachandran S,
Cann HM, Barsh GS, Feldman M, Cavalli-Sforza LL, Myers RM.
Worldwide human relationships inferred from genome-wide
patterns of variation. Science. 2008 Feb 22;319(5866):1100-4.
Cann HM, de Toma C, Cazes L, Legrand MF, Morel V, Piouffre L, Bodmer
J, Bodmer WF, Bonne-Tamir B, Cambon-Thomsen A et al.
A human genome diversity cell line panel.
Science. 2002 Apr 12;296(5566):261-2.