【精英翻譯】的部落格

Meat eating accelerated face evolution 吃肉加速臉部演化

精英翻譯社轉自http://iservice.ltn.com.tw/Service/english/english.php?engno=993566&day=2016-05-25

◎魏國金

Eating raw meat and making stone tools may be behind the smaller teeth and faces of humans compared with their ancient relatives.

吃生肉與製造石器或許是人類的牙齒與臉型比其遠古近親還小的因素。

Meat and tools, not the advent of cooking, was the trigger that freed early humans to develop a smaller chewing apparatus, a study suggests. This in turn may have allowed other changes, such as improved speech and even shifts in the size of the brain.

在烹煮尚未出現前，肉與工具是促使早期人類發展出較小咀嚼構造的因子，一項研究顯示。這或許因此使其他改變得以發生，例如說話能力的提升，甚至腦部大小的變化。

The authors conclude that cooking became commonplace much later.

該研究撰文者結論說，烹煮要到很後來才變得尋常。

Prof Daniel Lieberman and Dr. Katherine Zink from Harvard University have published their work in the journal Nature.

哈佛大學的李伯曼教授與辛克博士將其研究成果發表於「自然」期刊。

By the time the species Homo erectus appeared about two million years ago, humans had evolved bigger brains and bodies that had increased our daily energy requirements.

在約200萬年前直立人出現的時代，人類已演化出較大的腦與軀體，增加我們每日能量的需求。

But paradoxically, they had also evolved smaller teeth, as well as weaker chewing muscles and bite force. They also had a smaller gut than earlier human ancestors.

但矛盾的是，他們也演化出較小的牙齒，以及較弱的咀嚼肌與啃咬力。他們也有比起較早的人類祖先更小的腸子。

One of the possible reasons for these changes, cooking, did not become commonplace until 500,000 years ago, the researchers found.

導致這些變化的可能原因之一是，烹煮要到50萬年前才成為司空見慣，研究人員發現。

The findings suggest that by eating a diet of one-third meat, and using stone tools to process the food - slicing the meat and pounding the plant material - early humans would have needed to chew 17％ less often and 26％ less forcefully.

該研究因而推測，由於生肉佔3分之1的飲食，以及利用石器處理食物──切割肉類與搗碎植物食材──早期人類減少17％咀嚼次數與26％的咀嚼力道。