一项解剖学研究显示了人族踝关节的细节,并表明了现代人的祖先没有类似于灵长类的树木攀援技能。一些科学家认为早期人类可能以类似于黑猩猩在树间运动的方式行走和攀援。
美国莫西干大学Jeremy DeSilva拍摄并分析了乌干达的黑猩猩的录像,从而确定这种动物的骨骼运动是否符合早期人类攀援的主张。该作者把重点放在了踝关节上,利用这些录像确定了背屈角(背屈是指踝关节转动从而让脚趾指向上方)。DeSilva证明了黑猩猩的背屈比人类远远大得多;黑猩猩能弯曲45度,而人类的范围是15到20度。现代猿的胫骨下端与踝关节连接的地方有更宽的前侧面,这很可能是对背屈的一种适应。这组作者检查了生活在150万年到400万年前不同时代的人族的12个胫骨化石,结果没有发现这样的适应。再结合其他已知的人族骨骼细节,Desilva提出人类祖先即便能攀援,可能也不像黑猩猩那样攀援。(生物谷Bioon.com)
生物谷推荐原始出处:
PNAS April 13, 2009, doi: 10.1073/pnas.0900270106
Functional morphology of the ankle and the likelihood of climbing in early hominins
Jeremy M. DeSilva,1
Department of Biology, Worcester State College, Worcester, MA 01602; and Department of Anthropology, University of Michigan, Ann Arbor, MI 14809
Abstract
Whether early hominins were adept tree climbers is unclear. Although some researchers have argued that bipedality maladapts the hominin skeleton for climbing, others have argued that early hominin fossils display an amalgamation of features consistent with both locomotor strategies. Although chimpanzees have featured prominently in these arguments, there are no published data on the kinematics of climbing in wild chimpanzees. Without these biomechanical data describing how chimpanzees actually climb trees, identifying correlates of climbing in modern ape skeletons is difficult, thereby limiting accurate interpretations of the hominin fossil record. Here, the first kinematic data on vertical climbing in wild chimpanzees are presented. These data are used to identify skeletal correlates of climbing in the ankle joint of the African apes to more accurately interpret hominin distal tibiae and tali. This study finds that chimpanzees engage in an extraordinary range of foot dorsiflexion and inversion during vertical climbing bouts. Two skeletal correlates of modern ape-like vertical climbing are identified in the ankle joint and related to positions of dorsiflexion and foot inversion. A study of the 14 distal tibiae and 15 tali identified and published as hominins from 4.12 to 1.53 million years ago finds that the ankles of early hominins were poorly adapted for modern ape-like vertical climbing bouts. This study concludes that if hominins included tree climbing as part of their locomotor repertoire, then they were performing this activity in a manner decidedly unlike modern chimpanzees.