听力文本

Clack returned to Cambridge with dozens of tetrapod fossils.
Clack带着许多四足动物化石回到了剑桥
It meant that at last someone else would be able to do original work in the field of how we got our legs,
这意味着其他人终于可以对我们长出腿的事件进行初步研究
but the true importance of the trip did not emerge until 1990
但是这趟旅程的重要性直到1990年才显露出来
when a colleague, Mike Coats, started work on the specimen she'd almost thrown away, the acanthostega.
当时她的同事Mike Coats正开始研究这件几乎被她丢弃的标本，棘螈
He started to dig its hand out of the rock and he expected, of course, to find just five fingers.
他开始清除前爪周围的石头，当然，他希望看到5根趾
The first thing he found on this block was a finger. This digit here.
他在这块区域找到的第一样东西是一根足趾，就是这根趾

So we've got a number of finger bones aligned along the edge of this block.
我们可以看到这个地方排列着好几根趾
Then he continued with the preparation. He found the next finger which is here with its end curled over
后来他继续清理，他在这里发现了第二根趾，趾尖是弯曲的
and then a third similarly with this crooked finger end and a fourth, again with that,
接着是第三根，同样也有类似弯曲的趾尖，第四根，也是如此
and then there's a gap and then he went on to find another finger. Individual finger bones are really quite clear
接下来是一段空隙，他又找出了另一根趾头，每段趾骨都清晰可见
and that makes a total of five, but he still had all this area here to prepare so instead of stopping
这样他就找全了5根趾，但他还需要剖析这片区域，所以他没有停下来
he went on to clean up the rest of this area and lo and behold here is another digit, so that makes six
他继续清理剩下的部分，瞧，这看起来又是一根趾头，这样就是6根了
and he expected to finish there and then to his amazement here's a seventh and finally an eighth.
他以为这样就结束了，但是让他吃惊的是，这里还有第七根趾，最后是第八根
What? But it was true. Acanthostega had eight fingers on one hand.
怎么会这样？但这却是事实，棘螈的一个爪子上有8根趾

词汇解析

1.in the field of 在…方面，在…领域
He also did pioneer work in the field of weather observation.
他在气象观察领域也做了不少开拓性的工作。

2.dig out of 挖出；清除
It is a hole that you can dig yourself out of.
这是一个你能挖出的洞。

3.expect to do 期待做...
But how do you expect to do this? Through greater volume of sales? Or new technology?
但你期望如何达到这个目的？通过增加销量，还是使用新技术？

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”。