UCLA

Genetic information is indispensable in understanding several aspects of biology. In the first chapter of this dissertation, I reconstructed a phylogenetic tree from published gene fragments for the marmosets and tamarins (Callitrichidae) that I then used to reconstruct the biogeographic history of the group. Based on the results of this and previous studies, I recommended that the genus Saguinus be formally split into two genera, Saguinus and Leontocebus. In chapter two, I used high-throughput sequencing to genotype two exons of the MHC-DRB region in the sub- species Cebus capucinus imitator from Costa Rica. As in other reports on primate taxa, I found this gene region to be highly polymorphic and there is evidence of multiple copies of the DRB gene. I also found evidence for positively selected sites in both exons. In chapter three, I use ancient DNA extraction techniques combined with high-throughput sequencing to recover complete mitochondrial genomes for two extinct species of duck and place them into a phylogeny of living Anatidae. The first species, Chendytes lawi, is found to be the sister taxon to the tribe Anatini, despite all previous studies linking it to the tribe Mergini based on morphology. The second species, Camptorhyncus labradorius, is confirmed as a member of the tribe Mergini and is further shown to be the sister taxon to Polysticta stelleri, Stellar’s Eider.