听力文本

Darwin said the answer would lie out there in the rocks.
达尔文说过，答案就躺在岩石堆里
Somewhere there would be fossils that would explain everything.
某个地方的化石应该能解释一切
Palaeontologists would go scurrying all over the world trying to find them, but such early fossils are rare.
古生物学家们走遍了全世界，试图找到它们，可是这类古老的化石实在太少了
There's still so very, very few pieces of evidence.
目前的证据仍旧非常非常少
This is like one of those terrible classic murder mysteries, you know, that goes on for 30 or 40 years
就像那些经典的变态谋杀案，拖了三四十年都没能侦破
and people slowly trying to pick up a little bit of evidence, a little bit there.
人们只能慢慢地、一点一点地收集证据

But the more scientists looked the more they realised one crucial fossil was missing.
但是科学家们在寻找的过程中逐渐意识到他们缺少一块关键的化石
This would become a challenge to the whole Theory of Evolution and the story of how we got our legs
这成为对整个进化论的一大挑战，而有关我们如何进化出腿的故事，
would become the quest for the ultimate missing link.
也就变成了对“终极进化缺环”的追寻
The whole quest began 150 years ago with one simple observation.
整个搜索开始于150年前，起因只是一个简单的现象
A vast array of animals are, in fact, related. They all have four legs, they are tetrapods.
实际上大批动物都牵涉其中，它们都有4条腿，它们是四足动物

词汇解析

1.go on 持续
But I decided that if I kept silent it would go on for years and no one would do anything about it.
但是我下了决心，如果我保持沉默的话，这样的事情将持续几年，没有人会做任何事。

2.pick up 得到；学到
I will probably pick up some new ideas and understanding from them, which I'll relay to you, the next time we meet.
或许我将会从他们那儿学到一些新的想法和认识，所有的这些，在下次我们相遇的时候，我都会教给你。

3.the quest for 追求...
In the quest for youthful beauty, no treatment is too outlandish.
为了追求青春美丽，什么方法都称不上太古怪。

视频及简介

19世纪，英国生物学家赫胥黎在研究了尼安德特人的头骨以后，认为是一个具有猿脸的头骨，但决不是人与猿之间的中间缺环。这就告诉我们，人与猿之间的亲缘关系，似乎还应该有一环。1891年发现直立猿人（爪哇猿人）的骨胳，证明这个缺环确实是存在的。可是，日本的人类学家认为爪哇猿人尚不是真正的中间缺环。那么，在猿与人之间到底应该是什么样的一环呢？在埃塞俄比亚发现的早期人科动物化石，很可能是过渡物种。这一发现，弥补了原始人类进化中的一个“缺环”。