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The reasons for the major step forward in our evolution
人类进化中最重要一步的起因
are mired in controversy,
一直处在争论之中
but what is certain is that about 1.8 million years ago,
但可以肯定的是 大约180万年前
the first ancestor whose behaviour was truly human did emerge.
行为与人类很像的祖先 第一次出现了
This was Homo erectus.
那就是直立人
It had lost the ape-like characteristics of its predecessors,
他们已经没有了其先人那些类猿的特征
its anatomy was much like ours
其解剖结构与我们颇为相似
and it could run as easily as we can.
而且可以像我们一样奔跑
But crucially, its brain had grown by 20%.
更关键的是 大脑容量增加了20%
If Wrangham is right,
如果朗汉是对的
and cooking was the cause of this quantum leap,
烹饪确实是这巨大飞跃的推动力
it's crucial to find out when cooking started.
那么关键就是找出人类开始烹饪的时间
This is a matter of some debate.
这是个充满争议的问题
I think we first started cooking
我认为 大约200万年前
almost two million years ago with the origin of Homo erectus.
直立人开启了 人类的第一次烹饪
Cooking could possibly be one million years old.
烹饪可能已经有了百万年的历史
Based on the evidence we have,
根据我们现在所掌握的证据
I'd say we started to cook
我只能说人类
some time in the last 800,000 years.
在过去80万年里的某个时间开始烹饪

重点解释

The reasons for the major step forward in our evolution are mired in controversy,人类进化中最重要一步的起因一直处在争论之中

step forward站出来；向前进

He took a step forward in his career.

他的事业又向前迈进了一步。

We've made a big step forward in our studies.

我们在学习中前进了一大步。

it's crucial to find out when cooking started.那么关键就是找出人类开始烹饪的时间

find out发现；找出来；揭发

We must find out the customs of other countries, so that they will not think us ill mannered.

我们必须知道别的国家的习俗，免得他们会认为我们是没有礼貌的。

Find out what the conditions of the contract are.

弄清楚合同的条件是什么。