Researchers are turning their attention to the culinary habits of microbes in their search for a few chemical "crumbs" of evidence of ancient, remote, and even extra-terrestrial life. Scientists are analyzing rocks from the furthest reaches of Earth, and beyond, using new and sensitive instrumentation to check for tell-tale signs of ancient life.
In a paper in the April 8 issue of Science, a University of Rochester team has contributed to the effort. The scientists announced that they were able to re-create in the laboratory chemical signatures that were previously thought to be produced only by living organisms.
"The situation is a little more complicated than some people have thought," says geochemist Ariel Anbar, the lead investigator and an assistant professor of earth and environmental sciences and chemistry. "It's like someone saying that they have found a way to use fingerprints to identify people, and we're saying we can produce those same fingerprints in the lab without having that person around."
The work is part of an expanding worldwide effort to use increasingly sensitive chemical tools to look for signs of past life in remote places. Anbar's research focuses on the evidence that microbes leave behind after they munch on metals like molybdenum, copper, iron and zinc. The scientists say it's likely that as tiny organisms scour for these nutrients, they select certain isotopes of elements (isotopes are forms of the same element with a slightly different mass) over others, and the evidence is locked into rocks for millions of years. Researchers measure the amounts of different isotopes of certain metals as a way of knowing whether bacteria or other organisms once lived there.
It's a little bit like coming downstairs in the morning and finding the kitchen a mess, perhaps with the lid off a hidden cookie jar and crumbs on the counter. If the husband is the only person in the home who loves cookies and knows where the goodies are kept, th
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Contact: Tom Rickey
trickey@admin.rochester.edu
716-275-7954
University of Rochester
6-Apr-2000