A dental topographic analysis of chimpanzees

Molar tooth morphology is generally said to reflect a compromise between phylogenetic and functional influences. Chimpanzee subspecies have been reported to exhibit differences in molar dimensions and nonmetric traits, but these have not been related to differences in their diets. And in fact, observations to date of the diets of chimpanzees have not revealed consistent differences among subspecies. This study uses dental topographic analyses shown to reflect diet-related differences in occlusal morphology among primate species, to assess within-species variation among chimpanzee subspecies. High-resolution casts from museum collections were examined by laser scanning, and resulting data were analyzed using GIS algorithms and a two-factor ANOVA model. Although differences were noted between wear stages within subspecies in surface slope, relief, and angularity, none were found to distinguish the subspecies from one another in these attributes. This might reflect limitations in the ability of this method to detect diet-related differences, but is also consistent with a lack of differences in functionally relevant aspects of occlusal morphology among chimpanzee subspecies.