原文视听

Six million years ago, deep in the heart of Africa,
六百万年前非洲大陆的腹地
ancient humans started to walk upright.
古人开始直立行走
Professor Travis Pickering is on their trail
特拉维斯·皮克林教授正追寻着古人的足迹
to discover how our species evolved.
来探索人类进化史
Well, this is a type of early human ancestor
这是早期人类祖先的一种
that we call Australopithecus.
叫做南方古猿
We know it's a human ancestor,
之所以判定它是人类祖先
because we have indication
因为我们有证据显示
that it walked upright like us,
它像我们一样直立行走
but otherwise it's very ape-like.
但是不管怎么说它都是类人猿
It has a relatively small brain and a large projecting face.
大脑相对较小 还有张突出的大脸
Then about 2.3 million years ago,
在大约230万年前
there was a transformation.
进化再次发生
This is a species of early human that we call the handy man.
这是一种被称为"巧人"的早期人类
Its scientific name is Homo habilis.
学名叫做"能人"
We call it the handy man,
俗称为"巧人"
because it's associated with stone tools.
因为他们擅于使用石制工具
You can see that we have brain expansion
可以看到 大脑开始变大
and a smaller face that's tucked up under the skull.
颅骨下方的脸 则变小了
Finally, about 1.8 million years ago,
最后 在大约180万年前
our first truly human ancestor arrived -
人类第一位真正意义上的祖先出现
Homo erectus.
直立人

重点解释

because it's associated with stone tools.因为他们擅于使用石制工具

associated with 与…相联系，与 ... 有关

I associated with him in business.

我过去和他合伙经商。

He was briefly associated with that organization.

他同那个组织有过短时间的联系。

and a smaller face that's tucked up under the skull.颅骨下方的脸 ，则变小了

tuck up掀起，折起，卷起

Please tuck up the chair and put it side.

请把椅子折起来放在一边。

Please help me tuck up my sleeves.

请帮我卷起袖子。