Regional variation in the postcranial robusticity of Late Upper Paleolithic humans

The analysis of upper and lower limb robusticity of Late Upper Paleolithic non-European human skeletal samples was performed to assess the postcranal variation in geographic regions across the Old World. The differences in appendicular robusticity between Late Upper Paleolithic regional samples were interpreted within the framework provided by the European Upper Paleolithic human fossil record, where chronological trends in postcranial robusticity are exhibited. These trends include an increase in upper limb robusticity and a decrease in anterior-posterior lower limb strength. This variation is seemingly related to behavioral changes that indicate resource intensification and decreased mobility.; Robusticity of the humeri, femora and tibiae was analyzed primarily using diaphyseal cross-sectional biomechanical properties. Data were collected on forty Early Upper Paleolithic (EUP), 121 Late Upper Paleolithic (LUP) and 274 recent humans representing Europe, Africa and Asia. Residual and ratio analyses were used to examine the association between mechanical loading and diaphyseal cortical bone and to address regional and temporal variation in the Paleolithic. Specifically, two issues were addressed: (1) what are the patterns of regional variation in human postcranial robusticity across the Old World during the LUP? And (2) what are the temporal trends in the postcranial robusticity of non-European Paleolithic samples?; The results of these analyses revealed that the LUP was a period of regional differentiation, with geographical samples showing characteristic trends in robusticity features. Despite these differences, there is a general similarity in LUP groups relative to the EUP sample. Relative to EUP humans, all post-glacial samples show maintenance of right humeral robusticity and an increase in left humeral robusticity, resulting in decreased bilateral asymmetry in all LUP groups. However, in the lower limbs, all LUP samples show increasingly circular femoral midshaft sections due to reduced anterior-posterior bending strength relative to the EUP sample. This uniformity in robusticity across regional samples at the end of the Pleistocene suggest that there were universal changes in subsistence behavior and mobility after the glacial maximum that are most consistent with broad-spectrum exploitation of local and regional resources.