Abstract # 216:

Scheduled for Saturday, August 19, 2006 09:15 AM-09:30 AM: Session 20 (Regency East #3) Oral Presentation

Natural hybridization between howler monkeys in Mexico

L. Cortés-Ortiz1, E. Bermingham2, D. Canales-Espinosa3, F. García-Orduña3 and E. Rodríguez-Luna3
1University of Michigan, Museum of Zoology and Department of Ecology and Evolutionary Biology, 1109 Geddes Avenue, Ann Arbor, Michigan 48109-1079, USA, 2Smithsonian Tropical Research Institute, 3Universidad Veracruzana
     Natural hybridization among primates is relatively well known for Old World monkeys in which hybridization can occur at intra- and interspecific levels and even between individuals of different genera. Among Neotropical primates most reports of hybridization are between populations of the same species or between closely related species in which the taxonomic status of the species is questionable. We present genetic evidence of hybridization of two morphologically and genetically distinct Mesoamerican primate species, Alouatta palliata and A. pigra, in southern Mexico. We genetically characterized 104 individuals from 26 groups in 17 localities throughout the range of distribution of the two species by sequencing a fragment of the mitochondrial cytochrome b gene and genotyping individuals for eight microsatellite loci. Based on these data, 13 individuals were either hybrids or backcrosses between hybrids and one of the parental species. The presence of A. pigra-like mitochondrial haplotypes in all adult hybrids/backcrosses suggests that hybridization is unidirectional. Only one out of 34 microsatellite alleles showed evidence of introgression, suggesting that hybridization between these species is a recent phenomenon. Because hybrid individuals have only been identified within fragmented areas, the evidence of recent hybridization suggests that reproductive isolation among these species has broken down due to habitat fragmentation and provides a model for exploring the evolution of reproductive isolation in primates. Supported by PROMEP UVER 98-11-019, 103.5/03/1154EXB-9, UV, and STRI.