Experimental Studies on Primate Locomotion

一百多年来，人类学家、比较解剖学家和古生物学家一直在从化石记录中寻找证据。研究非人类灵长类动物的形态，以了解人类的祖先如何、为什么以及何时成为习惯性的熟练两足动物。在这一努力的早期，似乎这个问题的答案；可能是人类祖先的臂展或手臂摆动的行为预先适应并使他们倾向于两足行走。关于猿类自然行为的最新资料几乎不能支持这一理论，因此必须作出新的尝试，以发现产生人类的这种形式的可能行为。由于化石记录目前提供的直接与这个问题有关的数据有限，而且现有的数据已经导致了关于最早的人类在成为熟练的两足动物的道路上所经过的阶段的相互矛盾的解释，因此必须把重点放在确定以下方面的功能意义上：(1)最古老古人类化石的骨骼特征；(2)人类与非人类灵长类动物的解剖学相似性；(3)人类独有的解剖学特征。肌肉功能的特定假设，以及骨骼变化可能影响这种功能的方式，只能通过体内生理技术进行测试。拟议的研究将应用遥测记录非人灵长类动物在正常的树动行为、陆地运动和两足行走时的肌肉活动（适当时结合力-位置和运动学分析），以确定单个肌肉在这些行为中的实际作用。在这样做的过程中，更好地理解可能使人类祖先预先适应或预先倾向于两足行走的变化。同样的方法将应用于人类在广泛的双足活动中独特的人类肌肉的研究。结合非人类灵长类动物和人类的数据，将为解释从早期古人类骨骼结构的化石证据中推断出的肌肉附着、方向和大小的差异提供一个更健全的基础。

For over a hundred years, anthropologists, comparative anatomists and paleontologists have sought evidence from the fossil record and from; studies on the morphology of nonhuman primates in order to understand how, why, and when the ancestors of living humans became habitual accomplished bipeds. Early in this endeavor it seemed that the answer to this question ;might be that the practice of brachiation, or arm-swinging, by human ancestors preadapted and predisposed them for bipedalism. Recent information on the natural behaviors of apes lend little support to this theory, land new attempts must be made to discover the probable behavior of the form which gave rise to humans. Since the fossil record currently provides limited data bearing directly on this question, and the data which do exist have led to contradictory interpretations about the stages through which the earliest humans passed on their path to becoming accomplished bipeds, emphasis must be placed on determining the functional significance of: (1) osteological features characterizing the oldest fossil hominid, (2) anatomical similarities between humans and nonhuman primates, and (3) those anatomical traits that are unique to humans. Specific hypotheses of muscle function, and the ways in which bony changes might influence such function, can only be tested by in vivo physiological techniques. The proposed study will apply telemetered recording of muscle activity (combined, when appropriate, with force-place and kinematic analyses) in nonhuman primates during regular arboreal locomotor behavior, terrestrial movement, and bipedalism in order to establish the actual roles of individual muscle in these behaviors. In so doing, a better understanding of changes that might have preadapted or predisposed a human ancestor for bipedality is sought. The same methodology will be applied in humans to a study of uniquely human muscles during a wide range of bipedal activities. Combined data nonhuman primates and humans will provide a sounder basis for interpreting the differences in muscle attachment, orientation, and size that can be deduced from fossil evidence of early hominid skeletal structure.