SSS 2008-05-22(在线收听) |
This is Scientific America's 60-Second Science, I'm Cynthia Graber. This'll just take a minute. It’s hot to research life in extreme environments. There are organisms that thrive in boiling hot thermal vents and in toxic stews. These extremophiles, as they’re called, might show how life could arise on other planets. Or they may provide info that helps solve environmental crises. A newly discovered extremophile is described in the May 23rd issue of the journal Science. Based on genetic analysis, it appears to be a type of archaea—a single-celled organism similar to but distinct from bacteria. The microbe lives about a mile below the ocean floor, in temperatures ranging between 140 to 212 degrees Fahrenheit. There they munch on methane and other hydrocarbons. They thus beat all previous sub-seafloor-life records for extreme conditions—twice as deep, twice as hot, and in sediment three times as ancient, more than 110 million years old. Scientists think that more than two-thirds of all the earth’s prokaryotes might live beneath the ocean floor. So they need to dig even deeper for a fuller picture of life on earth—and under it.
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原文地址:http://www.tingroom.com/lesson/sasss/2008/5/98748.html |