(单词翻译:单击)
听力文本
Chimpanzees spend about half their day chewing.
"And for context, think about how much time a day you spend chewing."
Daniel Lieberman, a professor of human evolutionary biology at Harvard University.
"So how did we make that transition, from spending most of our day or half of our day chewing, to spending less than five percent?"
Cooking certainly tenderizes food, making it easier to chew and digest.
But evidence for human cook fires goes back only about 500,000 years, if that.
And Homo erectus had already evolved weaker jaws, and smaller teeth, more than a million years before that.
So Lieberman and his colleague Katherine Zink began their investigation by recreating a paleolithic dinner:yams, carrots, beets… and goat meat.
"If you were to try to eat some raw goat with your teeth you would find that you would chew and chew and chew, it's like bubblegum."
Lucky volunteers got to experience that, by chewing the food.
Either in its wild, un-tenderized state, or after it was bashed or sliced with Flintstonian tools.
As the study subjects ate, the researchers monitored the frequency and force of each chew.
And they found that a diet of abundant, pre-sliced meat, with a side of pounded root vegetables, might have saved Homo erectus two and a half million chews a year.
Meaning: less need for big, bulky jaws and teeth.
The research is in the journal Nature.
Of course, these days "processed food" has a pretty bad rap.
But for our ancestors, food processing was key.
"It's hard for people today to imagine what it was like to eat and cook and hunt during those times.
For the vast majority of our evolutionary history, our ancestors had to work pretty hard to chew their dinner."
Something for you to chew on, perhaps over dinner tonight.
参考译文
黑猩猩每天要在咀嚼食物上花掉将近一半的时间。
相比之下，想想你每天花多少时间用来咀嚼呢?
哈佛大学的人类进化生物教授丹尼尔·利伯尔曼说道。
“那我们是如何实现这种转变的呢？从一天吃东西花费大部分时间到现在大约不到5%的时间的呢?”
烹调确实让食物变得更软，更易咀嚼和消化。
但人类利用火进行烹调的证据只能追溯到大约500,000年前，如果的确如此的话。
而直立人进化出相对脆弱的下颌及小牙齿要比那个时候还早100万年。
因此利伯尔曼和他的同事凯瑟琳·辛克通过重新还原旧石器时代的一顿晚餐开始了对此的调查研究:山药，胡萝卜，甜菜，还有山羊肉。
如果你试着用牙齿直接吃生羊肉，你就会发现需要不停咀嚼，像在嚼泡泡糖一样。
参与这项研究的幸运志愿者们在咀嚼食物时有了这样的体验。
不管是野生，未经烹调，还是通过打火石工具敲打切碎后的食物都是这样。
而随着研究对象的进食,研究人员们对他们每次咀嚼的频率和力度进行了检测。
结果他们发现丰盛的一餐，肉类，根茎类蔬菜提前切好也许可以使直立人每年减少250万次咀嚼。
这就表明不需要巨大的，笨重的下颌以及牙齿。
这项研究已在《自然》杂志上发表。
当然，这些天加工食品的口碑不是很好。
但对我们的祖先而言，食物加工处理可是关键性的一环。
而现在的人们很难想象在当时那种条件下吃东西、烹饪及狩猎是什么样子。
在我们人类进化历史上很大一部分时间里，我们的祖先必须很努力的咀嚼自己的晚餐食物。
而对你而言，一顿晚餐或许要用一整晚才能搞定。
译文为可可英语翻译，未经授权请勿转载！
重点讲解
1.think about 思考
例句:I'll have a think about that.
我会考虑考虑的。
2.try to 尝试
例句:One child shrinks away from me when I try to talk to him.
当我试图和一个孩子说话时，他避开了我。
3.processed food 加工食品
例句:Imports: Machinery and equipment, processed food, chemicals, sugar and tea.
主要进口产品：机械设备、加工食品、化学产品、糖和茶。
4.work hard 努力工作
例句:I'll work hard. I don't want to let him down.
我会努力工作，我不想让他失望。
