万物简史 第409期:生命的起源(3)

 There are actually twenty-two naturally occurring amino acids known on Earth, 实际上，地救上有22种天然存在的氨基酸，

and more may await discovery, but only twenty of them are necessary to produce us and most other living things. 更多的尚待发现，但只有其中20种对我们及别的生物的形成是必不可少的。

The twenty-second, called pyrrolysine, was discovered in 2002 by researchers at Ohio State University 第22种叫做吡咯赖氨酸，是2002年由俄亥俄州立大学的研究人员发现的。

and is found only in a single type of archaean (a basic form of life that we will discuss a little further on in the story) called Methanosarcina barkeri.） 它只存在于太古代的巴氏甲烷八叠球菌之中（一种基本的生命形式，我们过一会儿还要讨论这个问题）。

How long would you have to pull the handle before all 1,055 symbols came up in the right order? Effectively forever. 你要拉多少次把手那1055个符号才地以合适的顺序排列起来？实际上，拉多少次都没有用。

Even if you reduced the number of spinning wheels to two hundred, which is actually a more typical number of amino acids for a protein, 即使你把转轮的数目减少到200个——这其实是蛋白质分子所含氨基酸分子的比较典型的数量，

the odds¹ against all two hundred coming up in a prescribed sequence are 1 in 10^260 (that is a 1 followed by 260 zeroes). 所有200个符号都按照特定的顺序来排列的概率是10的负260次方。

That in itself is a larger number than all the atoms in the universe. 那个数字本身比宇宙里原子的总数还要大。

Proteins, in short, are complex entities². 总之，蛋白质是十分复杂的实体。

Hemoglobin is only 146 amino acids long, a runt by protein standards, yet even it offers 10^190 possible amino acid combinations, 血红蛋白只有146个氨基酸分子长，按照蛋白质的标准只是个矮子，然而即使那样，氨基酸的排列方式也有10的190次方的可能性。

which is why it took the Cambridge University chemist Max Perutz twenty-three years—a career, more or less—to unravel³ it. 因此，剑桥大学的化学家马克斯·佩鲁茨花了23年时间——大体上相当于一个人的职业生涯——才解开了这个谜。

For random⁴ events to produce even a single protein would seem a stunning⁵ improbability, 想要随随便便地制造哪怕是一个蛋白质分子似乎是极不可能的——天文学家弗雷德·霍伊尔打了个精彩的比方，

like a whirlwind spinning through a junkyard and leaving behind a fully⁶ assembled jumbo jet, in the colorful simile⁷ of the astronomer⁸ Fred Hoyle. 就像是一阵旋风掠过一个旧货栈，后面留下了一架装配完好的大型客机。

1 odds   

n.让步，机率，可能性，比率；胜败优劣之别

参考例句：

• The odds are 5 to 1 that she will win.她获胜的机会是五比一。
• Do you know the odds of winning the lottery once?你知道赢得一次彩票的几率多大吗？

2 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。

3 unravel   

v.弄清楚（秘密）；拆开，解开，松开

参考例句：

• He was good with his hands and could unravel a knot or untangle yarn that others wouldn't even attempt.他的手很灵巧，其他人甚至都不敢尝试的一些难解的绳结或缠在一起的纱线，他都能解开。
• This is the attitude that led him to unravel a mystery that long puzzled Chinese historians.正是这种态度使他解决了长期以来使中国历史学家们大惑不解的谜。

4 random   

adj.随机的；任意的；n.偶然的(或随便的)行动

参考例句：

• The list is arranged in a random order.名单排列不分先后。
• On random inspection the meat was found to be bad.经抽查，发现肉变质了。

5 stunning   

adj.极好的；使人晕倒的

参考例句：

• His plays are distinguished only by their stunning mediocrity.他的戏剧与众不同之处就是平凡得出奇。
• The finished effect was absolutely stunning.完工后的效果非常美。

6 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

7 simile   

n.直喻，明喻

参考例句：

• I believe this simile largely speaks the truth.我相信这种比拟在很大程度上道出了真实。
• It is a trite simile to compare her teeth to pearls.把她的牙齿比做珍珠是陈腐的比喻。

8 astronomer   

n.天文学家

参考例句：

• A new star attracted the notice of the astronomer.新发现的一颗星引起了那位天文学家的注意。
• He is reputed to have been a good astronomer.他以一个优秀的天文学者闻名于世。