听力文本

By 1987 Clack was off to this apparent goldmine of tetrapods,
1987年，Clack出发前去寻觅这个显露的四足动物宝藏
taking along a student, Per Ahlberg. It was a big undertaking.
随行的是当时还是学生的Per Ahlberg，这是一项艰巨的任务
And of course it was possible that we were going to find almost nothing, or at least nothing new,
当然我们很可能一无所获，或者至少找不到新的东西
so the potential was there on the one hand for a spectacular success
所以那里的前景是一方面可能获得巨大的成功
and on the other hand for a considerable embarrassment.
另一方面也可能受到重重阻碍
At first it looked more like embarrassment.
一开始，看起来更像是受到了阻碍

As the week wore on, or the first two weeks wore on we still hadn't found the, the locality that we were looking for.
时间一天天过去，最初两周我们都没能找到我们一直寻求的地点。
We were beginning to think are we on the right mountain?
我们开始思考我们是不是爬错了山
Then Clack saw something.
后来，Clack有了发现
It was covered with dirt and soil. It very nearly got thrown on the scrapheap,
它被泥土覆盖住了，差点把它扔进了垃圾堆
but fortunately we brushed some of the dirt off and we could see part of a skull.
幸运的是，我们刷走了一些泥土，看到了一部分头骨
Clack's team had not found the transitional form between fish and tetrapods,
Clack的小组并没有找到鱼和四足动物之间的过渡型物种
but she had found something almost as rare.
但她却找到了另一种非常罕见的动物
It was another species of Devonian tetrapod, a species called acanthostega,
它是另一种泥盆纪四足动物，叫做棘螈
different from Jarvik's but clearly sharing the same 2ncestry and, therefore, also related to humans.
它和Jarvik的动物不太一样，但它们显然来自同一个祖先，所以它也和人类有关
Acanthostega was only the second complete Devonian tetrapod ever to be found.
棘螈是迄今发现的第二只完整的泥盆纪四足动物

词汇解析

1.be off to 去...地方
A lot of them will be off to summer camp for a week or 2 or more.
许多学生打算参加为时一周或数周的夏令营。

2.wear on 时间消逝
The hours wore on, the representatives became more anxious.
几个小时过去了，代表们更加厌烦了。

3.brushed off 刷去
Any life would be just brushed off, like ants off an apple.
任何生命都会被拂去，就像苹果上的蚂蚁一样。

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”。