A multivariate comparison of dental variation in wild and captive populations of baboons (Papio hamadryas)

Abstract

Phenotypic variation is critical to many aspects of biological research. Use of a captive population to address questions concerning the genetics and evolution of dental variation raises the question of how the pattern of phenotypic variation under study compares with that in a wild population of the same species. Differences in the pattern of variation within wild and captive populations may indicate different genetic and non-genetic factors, and also may have implications for how well the captive group can serve as a model for its wild type relatives. We compared dental size measures from two Papio hamadryas populations, one captive and one wild. Lengths and widths of maxillary and mandibular second molars (M2s) were collected from 630 baboons from a captive pedigreed breeding colony housed at the Southwest National Primate Research Center in San Antonio, Texas, and 125 baboons from a wild population culled from a sisal plantation in Kibweze, Kenya. Although the two populations consistently differed with respect to lengths and widths of the M2s, principal components analyses show that the basic pattern to variation in these molar crown traits is remarkably similar in both populations; and linear functions based on these measures cannot reliably discriminate between the two groups. This similarity in the pattern of variation among these dental crown measures in these two groups suggests that analyses to dissect their genetic architecture in captive populations is likely to be highly relevant to dental variation in wild baboons as well.

Figure 1

Plot of Linear Discriminant Function Scores from Analysis of 12 M2 Crown Metrics in Wild (W, triangle) and Captive Pedigreed Baboons (C, circle).