万物简史 第426期:生命的起源(20)

发表时间:2018-07-12内容来源:VOA英语学习网

This was most unexpected—so unexpected, in fact, that it was some years before scientists realized quite what they had found. Today, however, Shark Bay is a tourist attraction—or at least as much of a tourist attraction as a place hundreds of miles from anywhere much and dozens of miles from anywhere at all can ever be. Boardwalks have been built out into the bay so that visitors can stroll over the water to get a good look at the stromatolites, quietly respiring just beneath the surface. They are lusterless and gray and look, as I recorded in an earlier book, like very large cow-pats.

这完全是出乎意料的事——太出乎意料了,因此科学家们实际上过了几年才充分意识到自己的发现。然而,今天,沙春湾成了个旅游胜地——至少是一个不着边际的地方有可能成为的那种旅游胜地。用木板架成的人行道伸进了海湾,游客们可以在不的上方漫步,好好看一眼叠层石就在水面之下静静地呼吸。叠层石没有光泽,灰色,看上去很像个大团的牛屎。

But it is a curiously giddying moment to find yourself staring at living remnants of Earth as it was 3.5 billion years ago. As Richard Fortey has put it: "This is truly time traveling, and if the world were attuned to its real wonders this sight would be as well-known as the pyramids of Giza." Although you'd never guess it, these dull rocks swarm with life, with an estimated (well, obviously estimated) three billion individual organisms on every square yard of rock. Sometimes when you look carefully you can see tiny strings of bubbles rising to the surface as they give up their oxygen. In two billion years such tiny exertions raised the level of oxygen in Earth's atmosphere to 20 percent, preparing the way for the next, more complex chapter in life's history.

但是,望着地球上35亿年前留下的生物,这是个令人眼花缭乱的时刻。正如理查德·福泰说的:“这确实是跨越时间的旅行。要是世界与它真正的奇迹合拍的话,这个景致会和吉萨的金字塔一样知名。”虽然你根本不会去猜,但这些晦暗的岩石上充满了生命,据估计(哎呀,显然是估计),每平方米岩石上生活着36亿个微生物。要是你看得仔细的话,你有时候能看到一串串小气泡冒出水面。那是它们在释放氧气。在20亿年时间里,这咱小小的努力使地球大气里的氧增加到了20%,为生命史的下一章也是更复杂的一章铺平了道路。

来自:VOA英语网 文章地址: http://www.tingvoa.com/html/20180712/573094.html