原文视听

So we have cooking and we have small guts.
正是因为烹饪技术 人类才有了小肠道
This freed up energy for us to develop
这些多余的能量
what is arguably the most important organ in our body...
使我们身体最重要的一个器官 得以发展
the organ which, many would say, makes us human.
普遍认为 正是这一器官的发展造就了人类
Our brain.
那就是我们的大脑
The small gut big brain theory was developed
小胃大脑理论是由
by paleoanthropologist Professor Peter Wheeler.
古人类学教授彼得·韦勒提出的
We think that the smaller digestive system
我们认为 正是食物的转变
in Homo erectus was able to evolve because of the shift in diet,
使直立人的消化系统得以进化
freed up energy which could be used to power a larger brain.
这些多余的能量可以增强我们的脑力
And this is what we see,
我们可以看到
the increase in brain size in Homo erectus
直立人肠胃变小的同时
mirroring the reduction in the size of its gut.
脑部也开始变大
And it certainly does take a lot of energy to power our brains.
要增强我们的脑力 肯定得消耗很多能量
Although only 2.5% of our body weight,
尽管大脑重量只占体重的2.5%
when we're sitting, our brain consumes 20% of our energy.
即使坐着不动 脑部也会消耗我们20%的能量

重点解释

We think that the smaller digestive system in Homo erectus was able to evolve because of the shift in diet,我们认为，正是食物的转变使直立人的消化系统得以进化

able to能做 ...

I may be able to help you in some way.

我也许可以从某个方面去帮助你。

He was able to cast off such an uninteresting task.

他终于摆脱了这么一项乏味的工作。

because of因为； 由于

We win the game because of his participation.

由于他的参与，我们赢了比赛。

Because of his irresolute character, we were defeated at last.

因为他性格的软弱，我们最终被打败了。