And in terms of fishes -- fishes appeared 500 million years ago, and they're pretty modern, just 50 million years ago, so -- so interestingly, they give away their ancestry as they develop.
说到鱼类， 鱼类出现在5亿年前，而它们出现得相当晚， 大概5千万年前，所以， 有趣的是，它们在发展过程中抛弃了祖先遗传下来的东西。