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24 Cells
第二十四章 令人惊叹的细胞
It starts with a single cell. The first cell splits to become two and the two become four and so on. After just forty-seven doublings, you have ten thousand trillion (10,000,000,000,000,000) cells in your body and are ready to spring forth as a human being. Actually, quite a lot of cells are lost in the process of development, so the number you emerge with is really just a guess. Depending on which source you consult the number can vary by several orders of magnitude. The figure of ten thousand trillion (or quadrillion) is from Margulis and Sagan, 1986. And every one of those cells knows exactly what to do to preserve and nurture you from the moment of conception to your last breath.
生命开始于一个细胞。第一个细胞一分为二，二又分为四，以此类推，仅仅到第47次加倍以后，你就有了l亿亿（10000000000000000）个细胞，并作好了最终形成一个人的准备。事实上，在你的一生中，有许多细胞中途离你而去，因此你身上的细胞数只是一种估计。根据资料来源的不同，这个数字可能相差好几个数量级。1亿亿这个数字取自马古利斯和萨根的《微观世界》。从卵子受精的那一刻起，一直到你离开人世，为了维持和保护你，这些细胞中的每一个都完全知道自己的职责。
You have no secrets from your cells. They know far more about you than you do. Each one carries a copy of the complete genetic code—the instruction manual for your body—so it knows not only how to do its job but every other job in the body. Never in your life will you have to remind a cell to keep an eye on its adenosine triphosphate levels or to find a place for the extra squirt of folic acid that's just unexpectedly turned up. It will do that for you, and millions more things besides.
对于你的细胞来说，你无任何秘密可言，它们对于你的了解，远远超过你对自己的了解。每一个细胞都带有一整套基因密码——你身体的指令手册，因此它不仅知道怎样做自己的工作，而且对于你体内的其他任何一项工作，它都了如指掌。在你的一生中，你永远没有必要提醒任何一个细胞，要它随时注意其腺嘌呤核苷三磷酸盐的情况，或是找到存放不期然间出现的多余叶酸的地方。它将会为你做这样的一些事，以及几百万件别的事。
Every cell in nature is a thing of wonder. Even the simplest are far beyond the limits of human ingenuity. To build the most basic yeast cell, for example, you would have to miniaturize about the same number of components as are found in a Boeing 777 jetliner and fit them into a sphere just five microns across; then somehow you would have to persuade that sphere to reproduce.
每个细胞都是自然界的一个奇迹。即便是最简单的细胞，其构造的精巧程度也是人类的智慧所永远也无法企及的。举个例子，即便是制造一个基本的酵母细胞，你所需要的零部件就和一架波音777喷气式飞机的一样多，而且还必须在直径仅有5微米的球体内将它们组装起来，然后你还得以某种方式驱使那个球体进行繁殖。
