新奇事件簿 石器切割术加速人类进化（在线收听）

Eating habits and food processing skills from around two million years ago helped humans to evolve and develop language. Researchers from Harvard University say that learning to cut meat up and using basic stone tools to process food was a crucial step in our evolutionary process. The fact that we cut food up or pounded and crushed it meant we needed less time for chewing. This gave our mouths more free time to develop language and communicate. The researchers estimate that cutting up meat and other food saved early humans as many as 2.5 million chews per year. In contrast, the chimpanzee spends half of its day chewing, which means it has less time to communicate.

约200万年前，人类饮食习惯和食品加工技术促进语言发展。来自哈佛大学研究人员表示，在食品加工过程中，切割与基本石器技术是人类进化的重要一步。通过切割，锤击或砸击食物，人类缩短了咀嚼时间。并为语言发展，沟通交流留有更多时间。据研究人员预测，通过切割食物，每年节省咀嚼次数多达2500万次。但对于黑猩猩来说，每天一半时间用来咀嚼，沟通时间大大减少。

The researchers also said the shape of our face changed because we needed to chew less. Our jaws and teeth became smaller because we had learnt to cut up food. Professor Daniel Lieberman said: "We went from having snouts and big teeth and large chewing muscles to having smaller teeth, smaller chewing muscles, and snoutless faces. Those changes, and others, allowed for the selection for speech and other shifts in the head, like bigger brains." Dr Lieberman chewed raw goat meat to test his theory. He said: "You chew and you chew and you chew and you chew, and nothing happens." He added that to some extent, slicing meat into smaller pieces before chewing, "is the simplest technology of all".

据研究人员所述，由于咀嚼次数减少，人类脸型开始发生变化。由于切割术，下巴和牙齿体积变小。据丹尼尔·利伯曼所说：“从宽鼻大嘴到小鼻小嘴，从咀嚼肌发达到咀嚼肌薄弱。这些变化为沟通赢得空间，大脑等脑部活动也发生变化。”利伯曼通过咀嚼生山羊肉来验证理论。他认为：“在这一过程中，除了咀嚼还是咀嚼。”他还称在某种程度上，切割技术最为简单。”