海豚的聪明程度世界第二?

Today at Discovery News you can find out why dolphins are now believed to be the world's second most intelligent animals, with only humans displaying greater brainpower.
今天，在探索新闻里，我们将向您揭示为何海豚被认为是目前智力仅居于人类之后的、世界上第二聪明的动物。

Intelligence itself is a very loaded issue. It's difficult to compare one individual's brilliance with that of another within the same species, much less to attempt to compare intelligence among multiple species. Intelligence is just one component of a species' survival, so one can argue that spiders have evolved to be as smart as they need to be for their species to continue, rats are as brainy as they need to be, and so on.
智力本身就包含着许多复杂的因素.在同一物种中，都很难比较两个个体的智商的高下，更不必说在不同物种间了。智力是一个物种得以生存繁衍的条件之一。因此，我们可以认为，蜘蛛的智力水平进化到了这个物种能够得以生存的程度，老鼠等也是如此。

If human standards for intelligence are applied to non-human animals, however, dolphins come very close to our own brain aptitude levels, suggests Emory University dolphin expert Lori Marino.
埃默里大学海豚专家洛里马里诺说，如果把人类的智力水平评判标准应用到动物身上，则海豚的大脑资质水平和人类的十分相近。

She's performed MRI scans of dolphin brains. The scans prove dolphin brains are:
·big, relative to body size
·intricate, with a neocortex "more highly convoluted than our own"
·structured to allow for self-awareness and the processing of what Marino calls "complex emotions"
她对海豚的大脑进行了核磁共振扫描.结果显示，海豚的大脑有以下特征:
·大脑很大--相对于体形来讲；
·复杂--大脑皮质褶皱程度比人类的还要高；
·有产生自我意识的结构和处理圣马力诺所谓的“复杂的感情”的结构。

All animals share the capacity for emotions, she explained, but the part of the dolphin brain associated with processing emotional information is particularly expanded.
她说,虽然所有的动物的大脑都具备处理情感信息的能力，但是海豚大脑的这个能力特别强。

Why then did dolphins evolve to become so brainy?
那么为什么海豚的智商进化到如此之高呢？

Marino and her colleagues have analyzed modern dolphins and remains of ancient marine mammals to help answer that question.
马里诺和她的同事通过研究现代的海豚和古代海洋哺乳动物的化石，揭示了问题的答案。