Ancient ecosystem thrives millions of years below Antarct...( BOZEMAN Mont. -- Scientists have fou...)

BOZEMAN, Mont. -- Scientists have found an ancient ecosystem below an Antarctic glacier and learned that it survived millions of years by transforming sulfur and iron compounds for growth.

Described in the April 17 issue of Science, the ecosystem lives without light or oxygen in a pool of brine trapped below Taylor Glacier and next to frozen Lake Bonney in eastern Antarctica, said John Priscu, co-author of the Science article. Priscu is a longtime Antarctic researcher and professor in the Department of Land Resources and Environmental Sciences at Montana State University. The ecosystem contains a diversity of bacteria that thrive in cold, salty water loaded with iron and sulfur. The water averages 14 degrees Fahrenheit, but doesn't freeze because the water is three or four times saltier than the ocean.

The scientists made a breakthrough discovery when they learned that the bacteria convert key elements on Earth into food, Priscu said. The bacteria cycle sulfur compounds to access iron in the bedrock.

The ecosystem-- because it has been isolated for so long in extreme conditions -- could explain how life might exist on other planets and serve as a model for how life can exist under ice, Priscu said.

Jill Mikucki, lead author of the Science article and a former MSU graduate student, added that life below the glacier may help scientists answer questions about life on "Snowball Earth," the period when large ice sheets covered the Earth. The project also shows the power of multi-disciplinary collaborations, she said. Techniques in biogeochemistry, microbiology and molecular biology and other novel tests were used to figure out how the ecosystem could survive without photosynthesis.

The ecosystem has the "potential to be a modern analog to what geochemistry and biogeochemistry was like millions of years ago," Mikucki continued.