| dc.description.abstract | The genus Canis comprises at least six extant species of carnivores including human’s best friend: the domestic dog. Millions of years of natural selection and complex demography have shaped the genome of these taxa. While interspecific gene flow, bottlenecks and turn-overs are common amongst wild populations, the history of dogs have been dramatically affected by thousands of years of coevolution with humans and recent artificial selection. Therefore, reconstructing ancestry relationships and understanding the role of gene flow in the process of speciation has proven to be quite challenging, especially from modern genomes alone. Thus, I have analysed whole genome sequences of ancient, historical, and modern canids focusing on two case studies: the North American wolf-coyote complex and dogs from the Siberian Arctic. My findings suggest that interbreeding between wolves and coyotes is not a recent phenomenon caused solely by anthropogenic factors. In fact, my analyses show that both ancient and modern North American grey wolves have a higher genetic affinity with coyotes than Eurasian grey wolves, indicating a very long history of hybridisation between these species. Moreover, the establishment of endemic hybrid lineages such as the red wolf is likely the result of a speciation via hybridization event that took place during the Pleistocene instead of the result of hybrid swamping due to habitat disturbances and wolf persecution. In the case of Siberian dogs, my results show that changes in dog ancestry do not mirror human ancestry patterns. Although the ancestry of human ethnic groups appears to be continuous through time, the introduction of dogs from the Eurasian Steppe and Europe led to substantial admixture especially in the Iamal-Nenets region suggesting that Northwest Siberian communities were connected to a larger trade network and these exchanges may have contributed to major societal changes such as the rise of large-scale reindeer pastoralism. | en_US |
