一項解剖學研究顯示了人族踝關(guān)節(jié)的細節(jié),,并表明了現(xiàn)代人的祖先沒有類似于靈長類的樹木攀援技能,。一些科學家認為早期人類可能以類似于黑猩猩在樹間運動的方式行走和攀援。
美國莫西干大學Jeremy DeSilva拍攝并分析了烏干達的黑猩猩的錄像,,從而確定這種動物的骨骼運動是否符合早期人類攀援的主張,。該作者把重點放在了踝關(guān)節(jié)上,利用這些錄像確定了背屈角(背屈是指踝關(guān)節(jié)轉(zhuǎn)動從而讓腳趾指向上方),。DeSilva證明了黑猩猩的背屈比人類遠遠大得多;黑猩猩能彎曲45度,,而人類的范圍是15到20度?,F(xiàn)代猿的脛骨下端與踝關(guān)節(jié)連接的地方有更寬的前側(cè)面,這很可能是對背屈的一種適應,。這組作者檢查了生活在150萬年到400萬年前不同時代的人族的12個脛骨化石,,結(jié)果沒有發(fā)現(xiàn)這樣的適應。再結(jié)合其他已知的人族骨骼細節(jié),,Desilva提出人類祖先即便能攀援,,可能也不像黑猩猩那樣攀援。(生物谷Bioon.com)
生物谷推薦原始出處:
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.