Human Population Differentiation is Strongly Correlated With Local Recombination Rate

Abstract

Allele frequency differences across populations can provide valuable information both for studying population structure and for identifying loci that have been targets of natural selection. Here, we examine the relationship between recombination rate and population differentiation in humans by analyzing two uniformly-ascertained, whole-genome data sets. We find that population differentiation as assessed by inter-continental \(F_{ST}\) shows negative correlation with recombination rate, with \(F_{ST}\) reduced by 10% in the tenth of the genome with the highest recombination rate compared with the tenth of the genome with the lowest recombination rate \((P\ll10^{-12})\). This pattern cannot be explained by the mutagenic properties of recombination and instead must reflect the impact of selection in the last 100,000 years since human continental populations split. The correlation between recombination rate and \(F_{ST}\) has a qualitatively different relationship for \(F_{ST}\) between African and non-African populations and for \(F_{ST}\) between European and East Asian populations, suggesting varying levels or types of selection in different epochs of human history.