Evolutionary History, Phylogeography and Conservation Priorities for the Spider Monkey (genus Ateles)

Spider monkeys (Ateles) are one of the most endangered primates in the Neotropics. The genus is widely distributed from Mexico to the north of Bolivia and includes many morphologically distinct forms in terms of pelage color and patterning. The taxonomy, phylogenetic relationships, and biogeographic history of the genus have been subjects of much debate, which makes scientific communication difficult and raises challenges for conservation actions. The specific goals of this thesis were: (1) to infer the phylogenetic relationships among the different forms of spider monkeys and to explore their evolutionary history; (2) to test if currently recognized subspecies of the Mesoamerican spider monkey, A. geoffroyi form reciprocally monophyletic groups that are concordant with the contemporary classification; (3) to infer the phylogenetic relationships among different populations of Ateles geoffroyi to test if Pleistocene forest refugia theory can explain the diversity of spider monkeys in Mesoamerica; and (4) to use the information generated in this thesis to reevaluate the conservation status of different taxa of spider monkeys and to define priorities for conservation. In order to achieve these goals, I collected samples of spider monkeys across their geographic distribution and used ∼5 kilobases of the mitochondrial genome to conduct phylogenetic analyses. I inferred that all proposed species of spider monkey formed monophyletic clades. Ateles marginatus, was identified as the basal sister taxon to the rest of spider monkeys. Ateles geoffroyi and A. fusciceps appeared as two closely-related monophyletic clades. Within A. geoffroyi, my phylogenetic analysis revealed no concordance between putative subspecies names and the clades among samples, therefore a new classification needs to be proposed for this group. I also conclude that the Pleistocene Refugia hypothesis plays a partial role in explaining the evolutionary history and diversification of Mesoamerican spider monkeys. Finally, based on the information generated in this thesis, I suggest three taxa of spider monkeys (Ateles sp. indet. from El Salvador, A. azuerensis and A. f. fusciceps) as conservation priorities. These primates have small distribution areas, live in regions with highly degraded habitats, and enjoy minimal governmental protection. For these reasons, conservation strategies urgently need to be implemented to protect them.