Comparing the Landscapes of Independent Episodes of Introgression Among Primates

Miles Fancher and Aram Zaprosyan

Mentor: Dr. Rajiv McCoy

Supervisor: Stephanie Yan

Johns Hopkins University Department of Biology

Introgression refers to the transfer of DNA between two species that are closely related. Previous research in the field of evolutionary genomics has focused on looking at the prominent genes that have been introgressed from Neanderthals into the ancestors of modern humans and their lasting implications on humans today. Some research has been conducted towards investigating ancient introgression among primates, though there has been very little research in comparing such episodes of introgression. We used computational methods to compare episodes of primate introgression with each other as well as with the introgression that occurred from Neanderthals to humans. We did this by calculating the overlaps in genes introgressed between episodes of introgression. We found there was much more of an overlap of introgressed genes between episodes of introgression when the species involved were evolutionarily close to each other. These results reaffirm what previous research had developed regarding how the evolutionarily closer two species are, the more of their genetic structure will be the same. Future research can be conducted to expand this research with other mammal species to investigate associations between introgressed genes and evolution. This research is significant because it shows that there are associations between various episodes of primate introgression; certain introgression episodes can act as models for understanding other introgression episodes. Thus, studying episodes of ape introgression can provide valuable information about introgression into humans, since they have a high overlap in introgressed genes.