Relative joint size and hominoid locomotor adaptations with implications for the evolution of hominid bipedalism

摘要: The relationship between relative joint size and locomotor adaptations in living hominoids is examined using a variety of analytical strategies: narrow allometry, priori geometrical adjustments, empirical regression (allometric) adjustments. Regardless method, the observation that emerges conspicuously modern humans possess exceptionally large hindlimb lumbo-sacral joints for their body size. Full-time terrestrial bipedality precludes sharing weight support propulsion with forelimbs, this fundamental difference from other reflected human joints. Similar analyses including “Lucy” (A.L. 288-1, Australopithecus afarensis) suggest modest degree enlargement had already taken place at point hominid evolution, but highly-derived characteristic not yet been achieved. This implies adaptation to bipedalism early hominids was far complete functionally equivalent condition. It speculated later elongation lower extremity represent major adaptive shift linked advent longer distance travel evolution.