Added Williams, "Rock glaciers are not biological deserts as had been previously thought. This is one more example that microbes can live in the most extreme of environments."
Both the amount of dissolved organic matter and nitrate levels from microbial activity in the rock glacier rose dramatically from the late spring to the early fall in 2003, said Knauf. "This increase indicates that the biological signal is coming from meltwater inside the rock glacier, rather than from terrestrial microbial activity in the tundra around it," she said.
The dissolved organic carbon molecules from the rock glacier, which are large and complex, are very similar in structure to molecules found by the researchers in Antarctica, said Knauf. "The microbial activity we are seeing appears to be much more like what researchers have found in the Dry Valleys of Antarctica than anything found in North American temperate areas," she said.
Microbes, which are microscopic, single-celled organisms, have been found in boiling water in deep-sea ocean vents, clinging to ice in subterranean polar lakes and living in rocks two miles underground. Such microbes, known popularly as "extremophiles," also have been found living inside of nuclear reactors and even in the brickwork of 4,800-year-old Peruvian pyramids.
Because scientists suspect that Earth's most extreme environments resemble environments found on distant planets, such examples of extremophiles on Earth have caught the interest of astrobiologists, said Williams. "Parts of Antarctica are seen as an analog to environments on Mars by researchers, and we see this rock glacier environment as a new analogue to Antarctica," he said.
Microbes, which have been shown to metabolize elements like iron, nitrogen and sulfur, appear to require water in order to live, grow and reproduce. Previously at the Niwot Ridge study area, microbes living under the tundra sn
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14-Dec-2004