1Evolutionary Anthropology, Duke University, 2Institute for Human Evolution, University of the Witwatersrand
Thursday Morning, 301D
Neandertals and Homo sapiens are known to have substantially different upper limb morphology. Several morphological distinctions are attributed to disparity in behavioral repertoires, and are potentially indicative of shifts in behavior over the Pleistocene. However, other factors – e.g. allometry, ontogeny, phylogeny – must be considered during exploratory shape analysis before functional explanations may be attributed. The shape of the scapular glenoid fossa was compared among Neandertals, early and anatomically modern human populations, as well as chimpanzees and two species of Australopithecus. Geometric morphometric analysis revealed that Neandertals were morphologically most similar to active human populations. While overall size was significantly correlated with certain morphological aspects, many components of shape were not associated with allometric scaling. Considerations of outgroup taxa supported previous studies of evolutionary development and its influence on fossa shape, but a considerable degree of morphological variation remained unexplained. Articular rim morphology and fossa curvature were associated with other features previously attributed to function, particularly morphology of the glenoid notch. Bilateral analyses of a broad range of populations indicated the aforementioned morphologies drive asymmetry in active populations as well as for La Ferrassie 1. Thus, functional morphology may best explain these specific aspects of shape. This may be related to Neandertal subsistence strategy, particularly with respect to long-range projectile tool use.