[Show abstract][Hide abstract] ABSTRACT: Finite element analysis (FEA) is a potentially powerful tool by which the mechanical behaviors of different skeletal and dental designs can be investigated, and, as such, has become increasingly popular for biomechanical modeling and inferring the behavior of extinct organisms. However, the use of FEA to extrapolate from characterization of the mechanical environment to questions of trophic or ecological adaptation in a fossil taxon is both challenging and perilous. Here, we consider the problems and prospects of FEA applications in paleoanthropology, and provide a critical examination of one such study of the trophic adaptations of Australopithecus africanus. This particular FEA is evaluated with regard to 1) the nature of the A. africanus cranial composite, 2) model validation, 3) decisions made with respect to model parameters, 4) adequacy of data presentation, and 5) interpretation of the results. Each suggests that the results reflect methodological decisions as much as any underlying biological significance. Notwithstanding these issues, this model yields predictions that follow from the posited emphasis on premolar use by A. africanus. These predictions are tested with data from the paleontological record, including a phylogenetically-informed consideration of relative premolar size, and postcanine microwear fabrics and antemortem enamel chipping. In each instance, the data fail to conform to predictions from the model. This model thus serves to emphasize the need for caution in the application of FEA in paleoanthropological enquiry. Theoretical models can be instrumental in the construction of testable hypotheses; but ultimately, the studies that serve to test these hypotheses - rather than data from the models - should remain the source of information pertaining to hominin paleobiology and evolution.
Journal of Human Evolution 03/2010; 58(4):293-308. DOI:10.1016/j.jhevol.2009.12.001 · 3.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Here we compare dental microwear textures from specimens of the fossil genus Mesopithecus (Cercopithecidae, Colobinae) from the late Miocene of Eastern Europe with dental microwear textures from four extant primate species with known dietary differences. Results indicate that the dental microwear textures of Mesopithecus differ from those of extant leaf eaters Alouatta palliata and Trachypithecus cristatus and instead resemble more closely those of the occasional hard-object feeders Cebus apella and Lophocebus albigena. Microwear texture data presented here in combination with results from previous analyses suggest that Mesopithecus was a widespread, opportunistic feeder that often consumed hard seeds. These data are consistent with the hypothesis that early colobines may have preferred hard seeds to leaves.
Journal of Human Evolution 10/2009; 57(6):732-8. DOI:10.1016/j.jhevol.2009.06.009 · 3.73 Impact Factor