POSTCRANIAL SKELETON OF A MACAQUE TRAINED FOR BIPEDAL STANDING AND WALKING AND IMPLICATIONS FOR FUNCTIONAL ADAPTATION

The postcranial skeleton of a Japanese macaque that had been trained f or bipedalism over an 11-year period was studied. Considerable modific ations in the hindlimb bones caused by bipedal postural and locomotor behaviour were observed. Changes occurred in joint morphology, articul ar dimensions and shape-dependent strength of long bones, reflecting t he causal relationship between function and morphology. However, the c onditions under which the modifications are developed are somewhat dif ferent from those in humans, as the monkey's bipedalism is distinct fr om that of humans. The modifications seem to result from a compromise between functional requirements and the genetically determined anatomy of the essentially quadrupedal monkey.