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万物简史 第414期:生命的起源(08)

As one leading biology text puts it, with perhaps just a tiny hint of discomfort, "Researchers agree that such reactions would not have been energetically favorable in the primitive sea, or indeed in any aqueous medium, because of the mass action law." It is a little like putting sugar in a glass of water and having it become a cube. It shouldn't happen, but somehow in nature it does. The actual chemistry of all this is a little arcane for our purposes here, but it is enough to know that if you make monomers wet they don't turn into polymers—except when creating life on Earth. How and why it happens then and not otherwise is one of biology's great unanswered questions. 正如一篇重要的生物学文章所说,说得也许有点儿令人不大舒服:“研究人员一致认为,由于质量作用定律,在原始的大海里,实际上在任何含水的媒体里,这样的反应在能量方面是不大有利的。”这有点像把砂糖放进一杯水里,指望它结成一块方糖。这不该发生,但在自然界却不知怎的发生了。这一切的化学过程到底怎么样,这个问题已经超出了本书的宗旨。我们只要知道这样的一点就够了:要是你弄湿了单体,单体不不会变成聚合体——除了制造生命的时候。情况怎么是这样发生,为什么会发生,而不是那样发生?这是生物学上的一个没有回答的大问题。 One of the biggest surprises in the earth sciences in recent decades was the discovery of just how early in Earth's history life arose. Well into the 1950s, it was thought that life was less than 600 million years old. By the 1970s, a few adventurous souls felt that maybe it went back 2.5 billion years. But the present date of 3.85 billion years is stunningly early. Earth's surface didn't become solid until about 3.9 billion years ago. 近几十年来,地球科学方面有许多极其令人感到意外的发现。其中之一,发现在地球史早期就产生了生命。直到20世纪50年代,还认为生命存在不超过6亿年。到了70年代,几位大胆的人士觉得也许在25亿年前已经有了生命。但是,如今确定的38.5亿年确实早得令人吃惊。地球表面上是到了大约39亿年前才变成固体的。 We can only infer from this rapidity that it is not 'difficult' for life of bacterial grade to evolve on planets with appropriate conditions, Stephen Jay Gould observed in the New York Times in 1996. Or as he put it elsewhere, it is hard to avoid the conclusion that "life, arising as soon as it could, was chemically destined to be." “我们只能从这么快的速度推断,细菌级的生命在有合适的条件的行星上演化并不‘困难’。”斯蒂芬·杰伊·古尔德1996年在《纽约时报》上说,他在别的场合也说过,我们不得不下个结论:“生命一有可能会产生,这是化学上势必会发生的事。” 来自:VOA英语网 文章地址: http://www.tingvoa.com/html/20180613/565308.html