Explosive Pleistocene range expansion leads to widespread Amazonian sympatry between robust and gracile capuchin monkeys
Aim Capuchin monkey species are widely distributed across Central and South America. Morphological studies consistently divide the clade into robust and gracile forms, which show extensive sympatry in the Amazon Basin. We use genetic data to test whether Miocene or Plio‐Pleistocene processes may explain capuchin species’ present distributions, and consider three possible scenarios to explain widespread sympatry.
Location The Neotropics, including the Amazon and Atlantic Coastal Forest.
Methods We sequenced the 12S ribosomal RNA and cytochrome b genes from capuchin monkey specimens. The majority were sampled from US museum collections and were wild‐caught individuals of known provenance across their distribution. We applied a Bayesian discrete‐states diffusion model, which reconstructed the most probable history of invasion across nine subregions. We used comparative methods to test for phylogeographic association and dispersal rate variation.
Results Capuchins contained two well supported monophyletic clades, the morphologically distinct ‘gracile’ and ‘robust’ groups. The time‐tree analysis estimated a late Miocene divergence between Cebus and Sapajus and a subsequent Plio‐Pleistocene diversification within each of the two clades. Bayesian analysis of phylogeographic diffusion history indicated that the current wide‐ranging sympatry of Cebus and Sapajus across much of the Amazon Basin was the result of a single explosive late Pleistocene invasion of Sapajus from the Atlantic Forest into the Amazon, where Sapajus is now sympatric with gracile capuchins across much of their range.
Main conclusions The biogeographic history of capuchins suggests late Miocene geographic isolation of the gracile and robust forms. Each form diversified independently, but during the Pleistocene, the robust Sapajus expanded its range from the Atlantic Forest to the Amazon, where it has now encroached substantially upon what was previously the exclusive range of gracile Cebus. The genus Cebus, as currently recognized, should be split into two genera to reflect the Miocene divergence and two subsequent independent Pliocene radiations: Cebus from the Amazon and Sapajus from the Atlantic Forest.
Document Type: Research Article
Affiliations: 1: Center for Society and Genetics, University of California, Los Angeles, CA, USA 2: Wildlife Conservation Society, Rio de Janeiro, Brazil 3: University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, AK, USA 4: Department of Anthropology, New York University, New York, NY, USA 5: School of Biological Sciences, Washington State University, Pullman, WA, USA 6: Escuela de Biología, University of Costa Rica, San José, Costa Rica 7: Department of Anthropology, Washington State University, Pullman, WA, USA 8: Departamento de Biologia, Universidade Federal do Amazonas, Manaus, AM, Brazil 9: Division of Biological Sciences, University of Montana, Missoula, MT, USA 10: Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
Publication date: February 1, 2012