Body proportions and environmental adaptation in gorillas.

A variety of environmental factors likely contributed to observed patterns of morphological variation among extant gorillas. We interpret the short hand and foot bones of all G. beringei as genetic adaptations to greater terrestriality in the last common ancestor of G. beringei; variation in other limb lengths to climatic adaptation, both genetic and developmental; and the larger thorax of G. b. beringei to adaptation to reduced oxygen pressure at high altitudes, again as a product of both genetic differences and environmental influences during development.