Doctoral Dissertation Research: The phenotypic consequences of adaptive introgression in naturally hybridizing primates

Duke University, Durham NC

Investigators

Abstract

Recent findings suggest that intermixing with now-extinct relatives like the Neanderthals may have helped humans adapt to new environments during their rapid expansion around the globe, and may still contribute to human differences in disease susceptibility today. However, the extent to which benefits to hybridization are also found in other primates is not well understood. This doctoral dissertation project will use a model for natural hybridization in primates to investigate signatures of beneficial transfer of genetic variants between species. It will also ask whether hybridization affects hair color and maturation timing in baboons, traits that may be important in mate competition, fertility, or survival. The research will provide novel insight into hybridization’s role in primate evolution and shed light on how hybridization may influence primate diversity in the future. It will also contribute to STEM education at the elementary, undergraduate, and graduate levels through the design of new educational activities, mentored research opportunities for undergraduate students, and support for the co-PI’s PhD training. Finally, this project will facilitate public engagement with science through free-to-the-public presentations that will also be accessible online. To investigate the potential benefits of hybridization in primates, the project will integrate genomic and observational data from wild baboons. It will test the hypothesis that hybridization facilitates the transfer of a small number of advantageous genetic variants between yellow baboons and anubis baboons. To do so, genomic data will be generated for multiple populations spanning a baboon hybrid zone. These data will be subjected to three complementary methods to identify genetic variants affected by adaptive introgression. Cases of potential adaptive introgression will be investigated for overlap with genes that are also differentially expressed between yellow and anubis baboons. The project also will test the hypothesis that genetic ancestry predicts hair color and maturation timing in a well-studied baboon population at the center of the hybrid zone. It will assess whether ancestry effects on these traits differ in number and magnitude across the genome, based on evidence that hair and skin color traits tend to have a simpler genetic basis than life history traits like maturation timing. Finally, the project will test whether regions in the genome that contribute to ancestry-related differences in hair color or maturation timing are candidates for adaptive introgression. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.