Ecology and Evolutionary Biology, UCLA
April 14, 2016 9:30, Imperial Ballroom B
Wolf-like canids have remarkably fluid genomes. Hybridization is especially widespread among gray wolves and coyotes and between gray wolves and domestic dogs. For the latter pairing, admixture confounds simple reconstructions of demographic history and has contributed to adaptation in both species. In North American wolves, black coat color is common and due to a beta-defensin variant that evolved in domestic dogs and was transferred uniquely to North American wolves probably through interactions with Native American dogs. After this admixture event, the black coat allele was swept by natural selection to high frequencies in North American wolf populations. However, the function of the black coat color is not straightforward, and probably relates to immune response rather that coat color. For example, black wolves have a heightened resistance to canine distemper which in turn, is more common in wolves where nearby dogs provide a reservoir for the disease. Consequently dogs are both a genetic source for resistance and disease, which might explain the persistence of the black coat color variant in North American wolf populations. Wolf-dog admixture has also facilitated hypoxia adaptation in Tibetan gray wolves and mastiffs. Finally, admixture has produced substantial phenotypic diversity in coyotes and gray wolves, and hybrid zones in the Great Lakes area and southeastern US comprise an intermediate-sized canid, sometimes considered a distinct species. I integrate these observations into diagnosis of how admixture assists and hampers the process of evolution in wolf-like canids.
National Science Foundation, American Kennel Club