『新东方在线托福口语』为托福考生准备了ETS托福TPO/Official 18 Task 3口语练习：Relict Behavior &nbsp;
In general, animals 原文题目答案解析，TPO/Official 18 Task 3口语原文范文音频翻译。

托福TPO/Official 18 Task 3口语原文独立/综合口语题目答案解析-范文音频翻译-新东方托福官方网校手机版

旁白：现在听一下生物课讲座的一部分。

Narrator: Now listen to part of a lecture in a Biology class.

教授：好的，这是一个很好的例子，在北美，

Professor: Okay, so a good example of this found right here in North America,

is something an animal called the American pronghorn does.

你可能知道，叉角羚是一种像鹿一样的动物。

Pronghorns, as you may know, are a kind of deer-like animal.

它们住在开阔的草地上，在北美的中部，

They live out on the open grassy plains, somewhat in the middle of North America,

事实上，叉角羚是西半球最快的动物。

Pronghorns are in fact noted for being the fastest animal in the western hemisphere.

它现在的捕食者，如山猫或土狼，都不能指望能赶上它。

None of its present-day predators, like the bobcat or coyote can even hope to catch up with it.

好吧，那么为什么叉角羚跑得那么快呢？

Okay, so why then do pronghorns run so fast?

Well, it turns out that quite a long time ago,

草原上的东西曾经有很大的不同，

Things on the grassy plains used to be very different for the pronghorns,

因为在那时，狮子曾经生活在平原上，

because back then, lions used to live on the plains,

当然，狮子是一种移动非常快速的哺乳动物，

And lions of course, are a very swift-moving mammal,

或者是你今天在平原上发现的其他捕食者。

or other predators that you find on the plains today.

但是现在，狮子在北美已经灭绝了。

But now, however, lions are all extinct in North America.

现在已经没有叉角羚的捕食者了。

There are no longer a predator of the pronghorn.

the lions were there chasing the pronghorns.

所以在那时候，叉角羚的速度对它的生存至关重要。

So back then the pronghorn's speed was critical to its survival.

Relict Behavior &nbsp;
In general, animals act in ways that help them to survive within their specific habitats. However, sometimes an animal species may display a behavior that no longer serves a clear purpose. The original purpose for the behavior may have disappeared long ago, even thousands of years ago. These behaviors, known as relict behaviors, were useful to the animals when the species’ habitat was different: but now, because of changed conditions, the behavior no longer serves its original purpose. Left over from an earlier time, the behavior remains as relict, or remnant, long after the environmental circumstance that influenced its evolution has vanished.&nbsp;
 
<img src="/upload/ti/2427000-2428000/2427100/dd7fcd2de63c478cb53d274a93c3e7d6.jpg">
 &nbsp;
 Using the example of the pronghorn and lion, explain the concept of a relict behavior.
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