时差N小时 大象拥有超强记忆力（在线收听）

Don: Ready, Yael?

唐：真的吗，雅艾尔？

Yael: Yep.

雅艾尔：对。

Don: Here goes 3.1415 9265 3589 7932 3846 2643 3832 79. Ta da!

唐：听着，3.1415 9265 3589 7932 3846 2643 3832 79。哒哒！

Yael: Wow, you really can recite pi to the thirtieth decimal place. Very impressive, Don! You must have the memory of an elephant.

雅艾尔：哇，你真能背诵出圆周率小数点后十三位数字。唐，太令人印象深刻了! 你的记忆力肯定跟大象一样好。

Don: Thanks, Yael, but do elephants really have good memories? Or is that just a saying?

唐：谢谢，雅艾尔，但是大象真有很好的记忆力吗？或者这仅仅是个谚语？

Yael: Oh, it's real. In fact, a study on elephant memory shows that having a strong memory helps elephants survive in the wild.

雅艾尔：哦，是真的。实际上，一项对大象记忆力的研究证明拥有好的记忆力能帮助大象在野外存活。

Don: What do you mean?

唐：你是什么意思?

Yael: Well, scientists studying elephants in Tanzania's Tarangire National Park in Africa knew that some elephants lived through a terrible drought from 1958 to 1961. Now cut to 1993, when there's a second severe drought. Some elephant groups left the park, but only those with members who were old enough to have possibly remembered the earlier drought. The group that stayed in the park was composed of younger elephants.

雅艾尔：好吧，科学家对非洲坦桑尼亚的塔兰吉雷国家公园中的大象进行研究，了解到有些大象经历过1958年到1961年之间那次特大干旱。到1993年时，又一次严重的干旱袭来，一些大象群离开了公园，但仅仅是那些还记得之前的大干旱的老象所在的群体。留在公园的大象则是一群较年轻的大象。

Don: I see. And I assume that the elephants that left the park in 1993 were better able to survive.

唐：我明白了。我猜1993年离开公园的大象生存的机会更大。

Yael: Right. The elephants that left the park lost only ten- percent of their calves. But the group that stuck it out lost forty-percent of its young.

雅艾尔：没错。离开公园的那组大象只失去了10%的小象。而留下来的大象损失了40%的小象。

Don: So in this case, at least, evolution selects for elephants that have memories strong enough to remember stuff from their childhood.

唐：所以既然如此，至少大象进化选择了那些记忆力好得足以从儿时就记得事情的大象。

Yael: Yep. For elephants, memory is a survival tool.

雅艾尔：是的。对于大象来说，记忆是生存工具。