万物简史 第429期:生命的起源(23)

 Compared with the new eukaryotes the old prokaryotes were little more than "bags of chemicals," in the words of the geologist¹ Stephen Drury. 地球已经朝着真正有意思的行星迈出了第一步。与新的真核细胞相比，旧的原核细胞——借用英国地质学家斯蒂芬·德鲁里的话来说——不过是“几囊化学物质”。

Eukaryotes were bigger—eventually as much as ten thousand times bigger—than their simpler cousins, and carried as much as a thousand times more DNA². 真核细胞比它们比较简单的堂兄弟要大——最后要大1万售，能够多带1000倍的DNA。

Gradually a system evolved in which life was dominated by two types of form—organisms that expel oxygen (like plants) and those that take it in (you and me). 由于这些突破，生命渐渐变得复杂，结果创造了两种生物——排斥氧的（比如植物）和接受氧的（比如你和我）。

Single-celled eukaryotes were once called protozoa ("pre-animals"), but that term is increasingly disdained³. 单细胞的真核细胞一度被称做原生动物（意思是“动物之前”），但那个名称越来越遭人鄙弃。

Today the common term for them is protists. 今天，它们通常被叫做“原生生物”。

Compared with the bacteria that had gone before, these new protists were wonders of design and sophistication. 与之前的细菌相比，原生生物在模式上和复杂程度上都是个奇迹，

The simple amoeba, just one cell big and without any ambitions but to exist, 简单的变形虫只有一个细胞大，除了生存没有别的雄心壮志，

contains 400 million bits of genetic⁴ information in its DNA—enough, as Carl Sagan noted⁵, to fill eighty books of five hundred pages. 但在它的DNA中包含着4亿条遗传信息——正如卡尔·萨根指出的，足以写出80本500页的书。

Eventually the eukaryotes learned an even more singular trick. 最后，真核细胞学会了一种更加独特的把戏。

It took a long time—a billion years or so—but it was a good one when they mastered it. 这花去了很长的时间——10亿年左右，但它们一旦成为专家，那还是个挺不错的把戏。

They learned to form together into complex multicellular beings. 它们学会了结合在一起，形成复杂的多细胞生物。

Thanks to this innovation, big, complicated, visible entities⁶ like us were possible. 由于这项新的发明，像我们这样大而复杂的、可见的实体终于成为可能。

Planet Earth was ready to move on to its next ambitious phase. 地球这颗行星已经准备好进入下一个雄心勃勃的阶段。

But before we get too excited about that, it is worth remembering that the world, as we are about to see, still belongs to the very small. 但是，在为此感到过分激动之前，应该记住，我们将会看到，世界仍然是小生物的世界。

1 geologist   

n.地质学家

参考例句：

• The geologist found many uncovered fossils in the valley.在那山谷里，地质学家发现了许多裸露的化石。
• He was a geologist,rated by his cronies as the best in the business.他是一位地质学家，被他的老朋友们看做是这门行当中最好的一位。

2 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

3 disdained   

鄙视( disdain的过去式和过去分词 )； 不屑于做，不愿意做

参考例句：

• I disdained to answer his rude remarks. 我不屑回答他的粗话。
• Jackie disdained the servants that her millions could buy. 杰姬鄙视那些她用钱就可以收买的奴仆。

4 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

5 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

6 entities   

实体对像； 实体，独立存在体，实际存在物( entity的名词复数 )

参考例句：

• Our newspaper and our printing business form separate corporate entities. 我们的报纸和印刷业形成相对独立的企业实体。
• The North American continent is made up of three great structural entities. 北美大陆是由三个构造单元组成的。