Tuesday, August 07, 2007

Weird Science

Ancient organisms brought to life

Researchers took five ice samples of various ages from the Antarctic
Microorganisms locked in Antarctic ice for more than 100,000 years could return to life as glaciers melt, according to scientists.

Researchers in the United States melted ice samples ranging from 100,000-years old to eight million and were able to grow bacteria from the younger samples.

The findings were significant because scientists did not know until now whether such ancient, frozen organisms and their DNA could be revived at all or for how long cells are viable after they have been frozen.

Kay Bidle, assistant professor of marine and coastal sciences at Rutgers University, said: "The young stuff grew really fast. We recovered them easily... They doubled every couple of days."

By contrast, microbes from the oldest samples grew slowly, doubling only every 70 days.

The findings were reported in the online edition of the Proceedings of the National Academy of Sciences journal.

The research found that the DNA in bacteria deteriorates sharply after about 1.1 million years. Bidle said that after 1.1 million years the size of the DNA gets cut in half.

In the oldest ice it consisted of just 210 units strung together. Normally the DNA of the average bacterium has about three million units.

Studying the organisms helps in "understanding the geological and physiological limits of life on Earth under different conditions," Bidle explained in an interview with the Associated Press news agency.

"They live in every possible environment ... so learning about microbes and what they can withstand and what their limits are is important to understanding how the Earth works over long periods of time," he said.

Original article posted here.

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