Contrasting signals of selection at the EDAR gene in global and Latin American populations.

The EDAR gene is a classic target of positive selection in humans, mainly through the nonsynonymous variant rs3827760 (EDARV370A) associated with ectodermal traits. Using high-resolution data from the 1000 Genomes Project, we combined sliding-window F_ST, BayeScan, and extended haplotype homozygosity (EHH) analyses to examine global and Latin American patterns of differentiation. Globally, a strong signal of positive selection was confirmed at EDAR, dominated by the rs3827760 haplotype background and its extended linkage disequilibrium structure. In contrast, within Latin America, differentiation reflected admixture-driven haplotype persistence rather than contemporary selection. A genome-wide FST scan comparing individuals from the upper and lower quartiles of Native American ancestry showed that EDAR lies among the most highly differentiated regions in this contrast, consistent with ancestry-driven haplotype structure rather than post-admixture adaptive evolution. These results indicate that EDAR retains its evolutionary signature globally but not within recently admixed populations, where demographic history rather than selection shapes its genetic landscape.