1. VOA英语学习网
  2. 设首页|英语四级|千亿国际文娱网页版|英语日志|英文自我引见|英语话剧脚本
  3. 打包下载 | 千亿国际 | BBC打包 | 日语 韩语
  4. 手机版
  1. 千亿国际文娱
  2. 剑桥英语测验认证
  3. 外教口语面临面课程

万物简史 第414期:生命的来源(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.


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.


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."


来自:千亿国际文娱网页版_千亿国际文娱|www.qy449.com 文章地点: http://www.tingvoa.com/html/20180613/565308.html