Archaic Hominin Admixture Facilitated Adaptation to Out-of-Africa Environments

Bibliographic Collection: 
Publication Type: Journal Article
Authors: Gittelman, Rachel M.; Schraiber, Joshua G.; Vernot, Benjamin; Mikacenic, Carmen; Wurfel, Mark M.; Akey, Joshua M.
Year of Publication: 2016
Journal: Current Biology
Pagination: -
Date Published: 11/2016
Publication Language: eng
ISBN Number: 0960-9822
Keywords: adaptive, admixture, Denisovan, Human evolution, Hybridization, introgression, Neandertal

SummaryAs modern humans dispersed from Africa throughout the world, they encountered and interbred with archaic hominins, including Neanderthals and Denisovans [1, 2]. Although genome-scale maps of introgressed sequences have been constructed [3–6], considerable gaps in knowledge remain about the functional, phenotypic, and evolutionary significance of archaic hominin DNA that persists in present-day individuals. Here, we describe a comprehensive set of analyses that identified 126 high-frequency archaic haplotypes as putative targets of adaptive introgression in geographically diverse populations. These loci are enriched for immune-related genes (such as OAS1/2/3, TLR1/6/10, and TNFAIP3) and also encompass genes (including OCA2 and BNC2) that influence skin pigmentation phenotypes. Furthermore, we leveraged existing and novel large-scale gene expression datasets to show many positively selected archaic haplotypes act as expression quantitative trait loci (eQTLs), suggesting that modulation of transcript abundance was a common mechanism facilitating adaptive introgression. Our results demonstrate that hybridization between modern and archaic hominins provided an important reservoir of advantageous alleles that enabled adaptation to out-of-Africa environments.

Short Title: Current Biology