Year: 2025
Type: dissertation
Abstract: Hybridisation is a widespread phenomenon, documented extensively across animals, insects, and plants. Specifically, within primates, hybridisation was once thought to occur in only rare instances. However, more recent analyses using genomic methods have uncovered that hybridisation occurs in primates likely at higher rates than previously estimated. Additionally, research on hybrids has highlighted that novel loci can be subject to positive natural selection leading to adaptive introgression within populations post-admixture. Therefore, examination of the extent of hybridisation within primate taxa is needed to better understand the complex nature of admixture and to test for evidence of adaptive introgression. Here, I report on instances of admixture within two primate groups, Papio and Homo, using high-coverage, whole-genome analysis and bioinformatic methods. In the first chapter, I outline the occurrences of hybridisation and adaptive introgression in primates. In the second chapter, I describe the extent of cryptic admixture within a pedigreed, captive baboon colony using 881 high-coverage, phased and imputed whole genomes of olive, yellow, and olive-yellow hybrid baboons. I found that over 10 percent of the sequenced animals were incorrectly labelled in the pedigree, which has implications for future research done at the colony. In the third and fourth chapters I use high coverage, phased modern human genomes from 76 worldwide populations to identify archaic introgression within modern human circadian rhythm genes, and secondarily, within genes that have been associated with reproduction in both mice and modern humans. I found evidence that archaic segments introgressed into modern humans were likely adaptive in both circadian rhythm- and reproductive-associated genes and contributed to assisting modern humans as they adjusted to their new environments outside of Africa. In the last chapter, I summarise my findings and provide a concise list of limitations and suggestions for future research.
Source: TSpace (University of Toronto)
Author: Kendall, Christopher Jon Richard
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7132902256