Doctoral Dissertation Research: Evolution of the Extant and Fossil Colobine Primates

Cuny Hunter College, New York NY

Investigators

Abstract

The colobine monkeys, a group of primates closely related to apes and humans, are species-rich and widespread globally. Despite an abundant fossil record demonstrating a greater ecological and geographic range in the past, their evolution remains poorly understood. This project will first determine the evolutionary relationships between the fossil and living colobines, then use these newly understood relationships to test long-standing hypotheses about the evolution of colobine habitats, diet, distribution, and diversity. Using newer methods and including recently described fossil material will provide a much-needed update on colobine evolution from earlier analyses and contribute significantly to our broader understanding of primate evolution. The methods used in this project will be evaluated for their applicability to other areas of primate evolution as well, including early human evolution. This project will also provide multiple opportunities for mentorship and public outreach by using charismatic primates to discuss primate biology, human evolution, and evolutionary theory more broadly. Outreach will continue at events hosted by New York City public schools, CUNY colleges, and the American Museum of Natural History and research opportunities related to this project for high school, undergraduate, and master's students will be provided, emphasizing broadly applicable skills in computer coding, statistical analysis, critical thinking, and research design. All products of this project, including raw data and computer program scripts, will be made available in public repositories to encourage further work on these relatively under-studied primates. This project will explore the evolutionary history of the colobine monkeys, a widespread and diverse primate radiation. In contrast to the primarily folivorous and arboreal extant colobines, fossil colobines are known from a wider geographic range and exhibit a range of inferred substrate preferences and ecologies. However, the evolutionary context of this diversity is largely unknown as the relationships between the fossil and living colobines are still poorly understood. This project will first conduct a comprehensive phylogenetic analysis of the living and fossil colobine monkeys and subsequently use the inferred tree(s) to explore long-held hypotheses about 1) the evolution of substrate use, 2) the number, timing, and route of dispersals between continents, and 3) the pattern and timing of colobine diversification in the context of Mio-Pliocene climatic events. Fossil and extant colobines will be scored for phylogenetic analysis and a set of functional postcranial measurements will also be taken. Parsimony and Bayesian phylogenetic analyses will be performed on both the morphological data only and in total-evidence analyses incorporating molecular data. A Bayesian tip-dated tree will be generated and used to explore changes in diversity through time, examining possible correlations with major climatic events. Biogeographic history and the evolution of substrate preference will be explored by mapping character state changes and inferring ancestral states using both parsimony optimization and Bayesian modeling. Character matrices and program codes will be made available to allow the incorporation of this work into a broader understanding of Mio-Pliocene catarrhine evolution. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.