科學60秒:人類遠距離捕獵的秘密武器
來源：滬江聽寫酷
2011-09-30 10:00
“Stand up straight! And do something about that hair!” Annoying? Sure. But such ___1___ may have made humans what we are today. Because our upright stance, and relative lack of hair, may have enabled our human ancestors to run far and fast enough to capture their prey. So say scientists in the Journal of Human Evolution. [Graeme D. Ruxton and David M Wilkinson, "Thermo regulation and endurance running in extinct hominins: Wheeler’s models revisited"]
The idea that standing on two legs and ___2___ all that body hair might have helped early humans keep cool on the African savanna was first ___3___ in the late 1980s. But those early models had our ancestors standing still in a gentle breeze. Scientists simply didn’t have the computational power to assess what might happen when those early humans had to up and chase down a meal.
The new model ___4___ how hot a human would get running long and hard enough to outlast an animal galloping in the midday sun. And it shows that a hominin would have to have been as energetically efficient, and as hairless and sweaty, as we are today to ___5___. Homo erectus could probably have gone the distance, the scientists say. But Australopithicus probably didn’t have the legs.
【視聽版科學小組榮譽出品】
The idea that standing on two legs and ___2___ all that body hair might have helped early humans keep cool on the African savanna was first ___3___ in the late 1980s. But those early models had our ancestors standing still in a gentle breeze. Scientists simply didn’t have the computational power to assess what might happen when those early humans had to up and chase down a meal.
The new model ___4___ how hot a human would get running long and hard enough to outlast an animal galloping in the midday sun. And it shows that a hominin would have to have been as energetically efficient, and as hairless and sweaty, as we are today to ___5___. Homo erectus could probably have gone the distance, the scientists say. But Australopithicus probably didn’t have the legs.
【視聽版科學小組榮譽出品】
parental advice
shedding
trotted out
takes into account
avoid overheating
“站站好！你那頭發(fā)該修理修理了！”聽著反感么？必須的。但也許正是這樣的嘮叨成就了今天的人類。人類的站立姿態(tài)以及長度適宜的頭發(fā)有利于人類祖先跑得夠遠夠快來獵食。科學家們在《人類進化雜志》上發(fā)表了這一觀點。
站立姿態(tài)以及體毛的去除有助于生活在非洲熱帶草原的早期人類防暑降溫，這一觀點早在20世紀80年代末就提出來了。但早期對人類祖先的研究仍很模糊，科學家無法測算出早期人類在追捕獵物的過程中會發(fā)生什么。
新模型將正午烈日下，人類在漫長艱辛追捕獵物的過程中會產生多少熱量。結果顯示，未免過熱，祖先們的精力、毛發(fā)、汗液都和我們現在一樣。科學家說，直立人應該已經走得夠遠了，但南猿恐怕就沒那個福分咯~
