Astrobiology - Research Article from Macmillan Science Library: Space Sciences

This encyclopedia article consists of approximately 13 pages of information about Astrobiology.
This section contains 3,648 words
(approx. 13 pages at 300 words per page)
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Earth's Microbial Biosphere

Since the late 1980s, advances in genetics and molecular biology have radically altered scientists' view of the biosphere and the contribution of microbial life to planetary biodiversity. The opportunity to compare gene sequences from a wide variety of living organisms and environments has shown that living organisms cluster into one of three biological domains: the Archaea, Bacteria, or Eukarya. Each of these domains is made up of dozens of biological kingdoms, the vast majority of which are microbial. Species inferred to be the most primitive forms so far discovered are all found at high temperatures (greater than 80°C [176°F]) where they use simple forms of chemical energy. However, knowledge of Earth's biodiversity is still very much a work in progress. While biologists have sampled a wide range of environments, it is estimated that only a small fraction, perhaps 1 to 2 percent of the total biodiversity...

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This section contains 3,648 words
(approx. 13 pages at 300 words per page)
Buy the Astrobiology Encyclopedia Article
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Macmillan Science Library: Space Sciences
Astrobiology from Macmillan Science Library: Space Sciences. Copyright © 2001-2006 by Macmillan Reference USA, an imprint of the Gale Group. All rights reserved.
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