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和非人类灵长类动物的形态研究中寻找证据，以了解现存人类的祖先是如何、为什么以及何时成为习惯性的有成就的两足动物的。在这一努力的早期，似乎这个问题的答案；可能是人类祖先的手臂摆动练习预先适应了他们，并使他们倾向于两足行走。最近关于类人猿自然行为的信息几乎不支持这一理论，必须做出新的尝试来发现人类起源的形式的可能行为。由于化石记录目前提供的与这个问题直接相关的数据有限，而且确实存在的数据导致了对最早的人类在成为成熟的两足动物的过程中所经历的阶段的相互矛盾的解释，因此必须强调确定：(1)最古老的原始人类化石的骨学特征，(2)人类与非人类灵长类动物在解剖学上的相似之处；(3)人类特有的解剖特征。肌肉功能的具体假设，以及骨骼变化可能影响这种功能的方式，只能通过体内的生理学技术来检验。这项拟议的研究将对非人类灵长类动物在常规树栖运动行为、陆地运动和两足行走过程中的肌肉活动进行遥测记录(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，人们寻求更好地理解变化，这些变化可能已经使人类祖先预先适应或倾向于两足行走。同样的方法将应用于人类，研究在广泛的两足动物活动中独特的人类肌肉。非人灵长类动物和人类的联合数据将为解释肌肉附着、方向和大小的差异提供更可靠的基础，这些差异可以从早期人类骨骼结构的化石证据中推断出来。

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.