导读：日本研究人员3月21日指出，人类祖先之所以由四足行走变为站起来两足行走，其原因之一是为了用上肢尽量多地搬运食物，以便获得更多的珍贵食物。
人类直立行走是为获得更多食物
日本研究人员3月21日指出，人类祖先之所以由四足行走变为站起来两足行走，其原因之一是为了用上肢尽量多地搬运食物，以便获得更多的珍贵食物。
日本京都大学和英国剑桥大学的研究人员在新一期美国学术期刊《当代生物学》上报告说，他们在西非国家几内亚的野外实验点投放了一些平时很容易获得的坚果和一些珍稀坚果，然后对几只黑猩猩的行动进行观察。
结果发现，与单纯投放普通坚果相比，在混有珍稀坚果的时候，原本四足行走的黑猩猩更多选择两足行走，其如此改变的频率是前者的4倍。研究还发现，黑猩猩在盗取农田里的番木瓜时，有35%的时间改为两足行走。
研究小组成员、京都大学教授松泽哲郎由此推测，由于远古气候变化，森林面积变小，生存变得困难起来。人类祖先在突然遇到一些意想不到的珍贵食物时会相互争夺，这时两足行走可以解放上肢，有助于多抢到一些稀罕食物。久而久之这种选择成为常态，人类祖先的肢体结构随之发生改变。
Chimpanzee carrying behaviour and the origins of human bipedality
Susana Carvalho, Dora Biro , Eugénia Cunha, Kimberley Hockings, William C. McGrew, Brian G. Richmond, and Tetsuro Matsuzawa
Why did our earliest hominin ancestors begin to walk bipedally as their main form of terrestrial travel? The lack of sufficient fossils and differing interpretations of existing ones leave unresolved the debate about what constitutes the earliest evidence of habitual bipedality. Compelling evidence shows that this shift coincided with climatic changes that reduced forested areas, probably forcing the earliest hominins to range in more open settings [1]. While environmental shifts may have prompted the origins of bipedality in the hominin clade, it remains unknown exactly which selective pressures led hominins to modify their postural repertoire to include a larger component of bipedality [2]. Here, we report new experimental results showing that wild chimpanzees walk bipedally more often and carry more items when transporting valuable, unpredictable resources to lesscompetitive places.
文献链接：https://www.cell.com/current-biology/abstract/S0960-9822(12)00082-6
