The 84th Annual Meeting of the American Association of Physical Anthropologists (2015)

The impact of past climate cycles on the paleodemography of East African ungulates as inferred from genomic RAD-Seq data


1Department of Anthropology, New York University, 2New York Consortium in Evolutionary Primatology

March 28, 2015 , Gateway Ballroom 2/3/4/5 Add to calendar

Climate cycling and subsequent habitat shifts in East Africa have long been identified as potential drivers of evolutionary change. The impact of climatic variation on the fauna of the Plio-Pleistocene has largely been inferred through paleontological data, but new genetic tools to probe past population sizes have become available. As East Africa is a location integral to human evolution, understanding evolutionary histories of the taxa of East Africa will ultimately lead to a more comprehensive picture of how and why humans evolved as they did. To address questions of the relationship between climate and ecosystems, we used the latest genomic techniques to investigate population variance in three species of ungulates. By including species of ungulates that occupy different environmental niches, we sought to discover how these populations responded to climate events. Correlating inferred changes in population size with known climate events can ultimately give us a richer understanding of the delicate relationship between climate and ecosystems.

We extracted DNA from 26 museum specimens (skin and tissue associated with skeletal elements) of Oryx gazella, Equus quagga, and Equus grevyi from the Field Museum of Natural History and Yale’s Peabody Museum. Using restriction site associated DNA sequencing (RAD-Seq) with the enzyme PspXI on an Illumina HiSeq 2500 platform, we generated >1,000 single nucleotide polymorphisms from >40,000 loci. Effective population size variance over time was inferred using approximate Bayesian computation. Initial demographic analyses suggest shifts in effective population size associated with changes in paleoclimate.