1Anthropology, University of Tennessee, Knoxville, 2School of Natural Sciences, School of Social Sciences, Humanities and Arts, University of California, Merced
Thursday All day, Clinch Concourse
Baboons (Papio sp.) have been recommended as a primate model for investigating hybridity in hominid species, and especially for studies of craniofacial variability. Several species within the Papio genus are known to hybridize in the wild, and this behavior makes them ideal candidates for questions of species identification, when presence or degree of hybridity is unknown.
To develop a primate model for examining hybridity, finite mixture and discriminant analyses were applied to craniometric data (n =222) from four species: Papio hamadryas, Papio anubis, Theropithecus gelada and Mandrilllus leucophaeus. Both cluster and classification results indicate that baboons are not appropriate for the effective quantification of hybridity. These findings bring the taxonomic classification of P. hamadrayas and P. anubis into question, as these two groups were consistently classified together. Moreover, hybrid offspring of P. hamadryas and P. anubis present mid-parental values for all measurements, which is a signature expected for admixed groups rather than hybridizing species. Analyses examining scaled, pooled male and female data consistently group sexes together regardless of species, suggesting that sexual dimorphism overrides between-species distinctions . This pattern further implies that P. hamadryas and P. anubis are subspecies rather than separate species. Genetic evidence also supports this conclusion. New research has identified recent divergence between Papio groups in eastern Africa and has noted that mtDNA evidence conflicts with traditional baboon taxonomy. As morphogenetic data do not support species distinctions between P. hamadryas and P. anubis, these groups are not ideal species for developing useful models of hybridity.