We modeled the effect of drift and selection on specific variants by using the simuPOP library.31 We used the effective population size estimated from this study in the simulations and obtained the initial allele frequency for each marker from the observed data. We recorded the allele frequency every 50 generations for 500 generations (which roughly corresponds to 12,500 or 14,000 years ago if we assume a generation time of 25 or 28 years, respectively). Each scenario was replicated 1,000 times.