“适者生存”，一个几乎无可辩驳的口号。

"the survival of the fittest," a slogan that virtually preempted all debate.

《柯林斯英汉双解大词典》

随着世界气候的变迁，恐龙绝迹了，但许多较小的动物却继续活了下来。这就是适者生存。

With the changes in the world's climate, dinosaurs died, but many smaller animals lived on. It was the survival of the fittest.

《新英汉大辞典》

从进化角度来看，这一概念奉行“适者生存”的哲学。

The concept, drawing from evolution, espouses the philosophy of survival of the fittest.

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If evolution is survival of the fittest, nature red in tooth and claw, how could animals evolve moral feelings?

如果进化论是讲适者生存，在弱肉强食的自然界，动物怎么能进化出道德情感？

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