THE ROLE OF ECOLOGICAL FACTORS IN ODONTOMETRIC VARIABILITY AND ITS IMPLICATIONS FOR BODY SIZE ADAPTATIONS IN CERCOPITHECIDAE (AFRICA, MANDRILLUS, DENTAL)

This study examines metric variability of the post-canine dentition of four monkey groups (savannah and forest baboons, savannah and forest guenons) represented by 1,840 individuals in order to address several questions regarding the magnitude and bases of intraspecific variation in polytypic and sexually dimorphic primates. In addition, the relationship between tooth size and body size permits a consideration of the bases for variation in body size adaptations.;Simple geographic distance accounts for less than 3% of the odontometric variance. Different magnitudes of variability are not associated with broadly-defined ecozones: forest- and savannah-dwelling species have comparable intraspecific odontometric variability. Taxonomic status and/or sexual composition of a sample does not correspond to a particular magnitude of variability; therefore, the use of the coefficient of variation to assess either the specific or sexual composition of fossil samples is inappropriate.;For the odontometric variables examined here, the sample variance is strongly correlated with the sample mean across taxa of markedly different tooth and body size. Variance displays low but significant correlation with the mean in the guenon samples for the length dimensions, despite the relatively small size range of sample means. However, sample variance has no statistically significant linear relationship with the mean in the baboon samples for any dimensions.;Cercopithecus aethiops, C. mitis, and Papio all display marked intraspecific variation in tooth size, and presumably body size, that is related to variation in mean annual rainfall, temperature, and humidity. Up to 44% of the variance in tooth size can be explained by climatic variables, as shown by multivariate regression techniques. It is suggested that climate affects variability in tooth and body size by influencing the nature, quality, and abundance of the vegetation available as foodstuffs. Variation in body size correlated with changing climatic conditions may also reflect thermal stress adaptations.