3月21日,,日本京都大學(xué)和英國劍橋大學(xué)的研究人員在新一期美國學(xué)術(shù)期刊《當(dāng)代生物學(xué)》(Current Biology)上報(bào)告說,人類祖先之所以由四足行走變?yōu)檎酒饋韮勺阈凶?,其原因之一是為了用上肢盡量多地搬運(yùn)食物,以便獲得更多的珍貴食物,。
研究人員在西非國家?guī)變?nèi)亞的野外實(shí)驗(yàn)點(diǎn)投放了一些平時(shí)很容易獲得的堅(jiān)果和一些珍稀堅(jiān)果,,然后對(duì)幾只黑猩猩的行動(dòng)進(jìn)行觀察,。
結(jié)果發(fā)現(xiàn),與單純投放普通堅(jiān)果相比,,在混有珍稀堅(jiān)果的時(shí)候,,原本四足行走的黑猩猩更多選擇兩足行走,其如此改變的頻率是前者的4倍,。研究還發(fā)現(xiàn),,黑猩猩在盜取農(nóng)田里的番木瓜時(shí),有35%的時(shí)間改為兩足行走,。
研究小組成員,、京都大學(xué)教授松澤哲郎由此推測,由于遠(yuǎn)古氣候變化,,森林面積變小,,生存變得困難起來。人類祖先在突然遇到一些意想不到的珍貴食物時(shí)會(huì)相互爭奪,,這時(shí)兩足行走可以解放上肢,,有助于多搶到一些稀罕食物。久而久之這種選擇成為常態(tài),,人類祖先的肢體結(jié)構(gòu)隨之發(fā)生改變,。(生物谷Bioon.com)
doi:10.1016/j.cub.2012.01.052
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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.