Evidence for genetic and behavioral adaptations in the ontogeny of prehistoric hunter-gatherer limb robusticity

We analyzed the femoral and humeral midshafts of four prehistoric hunter-gatherer skeletal samples from four regions: Cis-Baikal, Siberia, Point Hope, Alaska, the central Japanese coast, and the South African Cape. Some statistically significant differences between populations manifest at birth or soon after. Some of this systemic patterning likely reflects adaptation of body shape to climate. Later Stone Age South Africans also appear to demonstrate low limb rigidity residuals as a result of growth towards a unique body type. Differentiation between populations also increases with age, pointing to functional adaptation as a result of behavioral differences. This proves largely concordant with other lines of evidence for differing levels of terrestrial and aquatic mobility in these populations.