Exploring Human Adaptations Through the Holocene by Tracking Allele Frequencies Through Time

Abstract

Historically, researchers have utilized modern genetic variation within and between populations to draw inferences on past adaptations to climate, diet, or disease. With the increasing availability of ancient human archeological samples, these evolutionary changes can now be investigated more directly. I designed a tool to visualize temporal changes in minor allele frequency using ancient human individuals from the Allen Ancient DNA Resource (AADR V50.0). I then used an Approximate Bayesian computation (ABC) based approach to infer the strength and timing of selection in candidate genes. The results are largely in concordance with published data for two single nucleotide polymorphisms (SNPs) in the TYK2 and LCT genes, which have previously been shown to be under negative and positive selection, respectively. Going forward, the visualization tool can be used to screen for new candidates of selection, which can be confirmed through the use of ABC.