評論
打印
Using the example of the pronghorn and lion, explain the concept of a relict behavior.
請以叉角羚和獅子為例解釋說明孑遺行為的概念。
Read a passage about Relict Behaviors from a biology textbook.
請閱讀這篇選自生物課本的關于孑遺行為的文章。
You will have 50 seconds to read the passage. Begin reading now.
你將有50秒的時間閱讀文章，現在開始計時。
Now listen to part of a lecture in a biology class.
請聽生物學課上的部分內容。
Ok, uh, so a good example of this, found right there in North America,
關于這個話題的一個很好的例子，正好就是在北美洲發現的，
is something an animal called the American Pronghorn does.
有一種叫美洲叉角羚的動物就是如此。
Pronghorns, as you may know, are a kind of deer-like animal,
你們可能知道，叉角羚是一種長得很像鹿的動物，
they live out in the open grassy plains, somewhat in the middle of North America, and they are super fast.
它們生活在開闊的草原上，主要集中在北美洲中部，跑起來超級快。
Pronghorns are, in fact, noted for being the fastest animal in the western hemisphere.
事實上，叉角羚被認為是西半球跑得最快的動物。
Once a Pronghorn starts running, zoom!
一旦叉角羚開始跑了起來，“噌”地一下就不見了！
None of its present predators, like the bobcat or the coyote, can even hope to catch up with it.
在它現在的天敵中，比如山貓或者狼，沒有一個有望追得上它的。
It's off in a flash! Ok, so why then do Pronghorns run so fast? That's the question.
它跑起來就像一道閃電，十分迅速！那么，叉角羚為什么要跑得這么快呢？這才是我們今天要討論的問題。
Well, it turns out that quite a long time ago,
原來，在很久以前，我說的可是數萬年前，
I'm talking tens of thousands of years, things on the grassy plains used to be very different for the Pronghorns.
對叉角羚來說那時候草原上的情況和現在非常不同。
Because back then, lions used to live on the plains, chasing and preying upon the Pronghorns,
因為那個時候，這片草原上還住著獅子，它們追趕捕食著叉角羚，
and lions, of course, are a very swift-moving mammal,
而獅子，毫無疑問是一種行動非常迅速的哺乳動物，
much faster than the bobcat or coyote or other predators you'd find on the plains today.
比山貓和狼或者如今能在草原上看見的其他食肉動物都要快得多。
But, now, however, lions are all extinct in North America, there're no longer a predator of the Pronghorn.
然而，現在北美洲的獅子都已經滅絕了，再也沒有專門捕食叉角羚的食肉動物了。
Tens of thousands of years ago, though, the lions were there chasing the Pronghorns.
可是數萬年前，獅子們還在不斷追趕著叉角羚。
So back then, the Pronghorn's speed was critical to its survival.
所以那個時候，叉角羚的速度決定著它的存亡。
