Postcranial morphology is commonly used as the basis for interpreting human behavioral and environmental adaptations in the past. Recent evidence suggests that diaphyseal morphology may be subject to climatic influences;​ further, there may be a selective gradient in which distal elements are subject to tighter climatic and biomechanical constraints than proximal elements are. Hence, the influence of climate and behaviour may differ throughout the skeleton.

This dissertation compares the postcranial robusticity of four groups of foragers, to elucidate behavioiural and climatic (quantified using effective temperature) influences on diaphyseal morphology. Foraging groups include early historic Andaman Islanders (n=32), Later Stone Age southern Africans (n=83), archaic foragers from southern Ontario (n=15) and late prehistoric Tierra del Fuegians (n=34). Diaphyseal cross-sectional geometry is quantified for the clavicles, humeri and ulnae bilaterally, and femora and tibiae unilaterally. Body size standardized geometric properties are compared using analysis of covariance and canonical variates analysis.

Climatic influences on skeletal robusticity are strong at some skeletal sites, especially the subtrochanteric femur location. The midshaft femoral shape and robusticity of the femur are strongly correlated with terrestrial mobility, among male and female subsamples. In the upper body, diaphyseal strengths are strongly correlated with marine mobility. There is no correspondence between tipper body bilateral asymmetry and material technology, but males have higher levels of asymmetry than females in all groups. Overall, diaphyseal robusticity corresponds with patterns of terrestrial and marine mobility. The positive relationship between robusticity and habitual behaviour is strongest in the distal limb elements. Thus, there is less disparity between observed morphological variability and functional adaptation in the distal elements.

This dissertation demonstrates that it is possible to partition climatic and behavioural influences on the skeleton. It is therefore possible to interpret habitual activity of foragers from diaphyseal robusticity.