Signature of recent positive selection upstream of the MEF2A gene. (A) The phylogenetic relationship of human, Neanderthal, chimpanzee, and rhesus macaque species. (Red arrow) Human lineage. The numbers show approximate divergence time in millions of years (Kumar and Hedges 1998; Pääbo 1999; Chen and Li 2001). (B) Proportion of human-derived SNPs measured using a 50-kb sliding window in the MEF2A gene region (red). SNPs were classified as derived according to the method described by Green et al. (2010). (Gray dashed line) Genome average. (Red arrow) Location, upstream of MEF2A, with significant excess of human-derived SNPs (one-sided Fisher's exact test, P = 0.00006). (C) Distribution of the proportion of human-derived SNPs for all windows across the human genome. (Red arrow) Probability of finding the observed proportion of human-derived SNPs in the location 50–100 kb upstream of MEF2A, estimated from the genome distribution.
