The Role of Geography in Human Adaptation
Figure 6
The distribution of XP-EHH, a measure of haplotype homozygosity, at high- FST SNPs in east Asians.
The solid line shows the distribution of XP-EHH [35] in the ASN population at SNPs with a frequency difference >90% between the ASN and YRI samples. For comparison, we plot the XP-EHH distribution both for SNPs randomly chosen from the HapMap and for simulated SNPs with a selective advantage of 1%. These analyses used the full HapMap data, but choosing only one high- FST SNP in genomic regions where there are clusters of high- FST SNPs (see Methods). Simulations applied the cosi demographic model with minor modifications [7, Methods]. SNPs simulated with selection were included if there was a frequency difference >90% between ASN and YRI and where the derived allele is at high frequency in ASN. Density curves were obtained using the default settings of the density function in R [95].