Abstract # 153:

Scheduled for Sunday, September 18, 2011 04:30 PM-04:45 PM: Session 22 (Meeting Room 410) Oral Presentation


PHYLOGEOGRAPHY OF BROWN SPIDER MONKEYS (ATELES HYBRIDUS) IN COLOMBIA: TESTING THE RIVERINE BARRIER HYPOTHESIS

L. Valencia1,2,3, A. Link1,2,3, C. D. Cadena4 and A. di Fiore1,2,3
1NYU, NY, USA, 2NYCEP, 3Proyecto Primates, 4Universidad de los Andes
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The diversification and phylogeny of spider monkeys have been explained by mechanisms such as geological fluctuations and ecological changes, but not by riverine barriers. Nonetheless, among brown spider monkeys (A. hybridus), two subspecies have been recognized based on differences in pelage coloration, divided by the Magdalena River in Colombia, suggesting their divergence could have been promoted by the river acting as a barrier. This study evaluates the influence of the river as a barrier to gene flow between different populations of A. hybridus in Colombia as well as the phylogenetic relationships and degree of genetic differentiation. Mitochondrial HV-1 and COII sequence variation from 11 populations along the two banks of the river were examined. Haplotypes were shared between populations on both banks and there wasn’t evident clustering of the samples in two supported clades, corresponding to each bank. All populations weren’t significantly differentiated and most of the genetic variation was observed within populations rather than between banks. Population genetic analysis showed gene flow between banks and a significant correlation between genetic and geographic distance, as predicted by the IBD model. There wasn’t a highly structured phylogeographic pattern and based on these mtDNA data, the riverine barrier hypothesis was not an important mechanism influencing the population genetic structure of A. hybridus, suggesting the Magdalena River hasn’t been a barrier to female-mediated gene flow in neutral markers.