万物简史 第597期:生命的物质(23)（在线收听）

Altogether, almost half of human genes — the largest proportion yet found in any organism — don't do anything at all, as far as we can tell, except reproduce themselves.

据我们所知，总共有近一半的人类基因——任何生物体内基因已知的最大比例——除了复制它们自己，它们根本不做任何事情。

All organisms are in some sense slaves to their genes. That's why salmon and spiders and other types of creatures more or less beyond counting are prepared to die in the process of mating. The desire to breed, to disperse one's genes, is the most powerful impulse in nature. As Sherwin B. Nuland has put it: "Empires fall, ids explode, great symphonies are written, and behind all of it is a single instinct that demands satisfaction." From an evolutionary point of view, sex is really just a reward mechanism to encourage us to pass on our genetic material.

从某种意义上讲，所有的生物都是其基因的奴隶。这就解释了为什么鲑鱼、蜘蛛以及其他数不清的生物在交配的同时也走向了死亡。繁殖后代、传递基因的欲望是自然界最强有力的冲动。正如谢尔文·B·纽兰所说：“帝国分崩离析，本我破壳而出，雄伟的交响乐笔下生成，这一切的背后是一种要求得到满足的本能。”从进化论的观点看，性本质上就是鼓励我们将基因传承给后代的一种机能。

Scientists had only barely absorbed the surprising news that most of our DNA doesn't do anything when even more unexpected findings began to turn up. First in Germany and then in Switzerland researchers performed some rather bizarre experiments that produced curiously unbizarre outcomes. In one they took the gene that controlled the development of a mouse's eye and inserted it into the larva of a fruit fly. The thought was that it might produce something interestingly grotesque. In fact, the mouse-eye gene not only made a viable eye in the fruit fly, it made a fly's eye. Here were two creatures that hadn't shared a common ancestor for 500 million years, yet could swap genetic material as if they were sisters.

科学家们好不容易接受了这样一个令人惊讶的事实，即我们DNA的绝大多数不做任何事情。紧接着，更意想不到的研究成果开始问世了。先是在德国，接着在瑞士，研究人员做了一系列奇怪的实验，其结果让人瞠目结舌。他们将控制老鼠眼睛发育的基因植入到果蝇的幼虫中。他们本来以为会产生某种有趣而怪异的东西，结果老鼠眼睛的基因不仅使得果蝇长出了一只老鼠的眼睛，同时也长出了一只果蝇的眼睛。这两类动物在长达5亿年的时间里分别拥有不同的祖先，但是它们却可以像姐妹一样交换基因。