Is Lake Vostok, buried in the Antarctic, bustling with life?
Scientists found 3,507 unique gene sequences in ice drilled from Lake Vostok, the world's largest subglacial lake.
Beneath some 13,000 feet of Antarctic ice is a world that should be lonely and empty. But, if a new study is correct, this subglacial lake could be teeming with hardy bacteria buried in one of the world’s most unusual environments.Skip to next paragraph
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Scientists from Bowling Green State University have recovered more than 3,000 gene sequences – some from complex organisms – from the ice of Lake Vostok, the world’s largest known subglacial lake. If the samples are found not to have been contaminated, the findings could be revolutionary, altering our understanding of life not only on our own planet but on alien worlds.
Lake Vostok lost contact with the atmosphere some 15 million years ago, and is not thought to be a homey place. The coldest natural temperature ever recorded on Earth – minus 126.6 degrees Fahrenheit – was taken on a mountain near the lake. Below the ice, the water is frigid, except around probable hydrothermal vents that bring it to a boil. The weight of the ice pressurizes the water to a lethal 350 atmospheres at the top of the lake, and even more so down below. The lake is completely dark, with few vital nutrients seeping down to its depths.
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But scientists have for years suspected that there could be life there. Astrobiologists – scientists who search for alien life – have suggested that organisms plumbed from those extreme conditions could offer models for what we might find on planets, where similarly unforgiving environments might beg of their inhabitants highly adaptive survival mechanisms that look nothing like the biological processes we know.
In 2008, a team led by Scott Rogers, a biology professor at Bowling Green State University, grew about 800 cultures from cells found in Lake Vostok’s ice. Those cultures correlated to about 50 different species and joined a small crop of studies, dating to about 1999, indicating that – improbably – the subglacial lake could have some residents.
"We knew that there was something down there," said Dr. Rogers, in a phone interview.
In his team’s most recent experiment, the results of which are published in PLOS ONE, Rogers and colleagues analyzed two ice core sections drilled from different sections of the lake, one from the southwestern region, which is about 10,000 years old, and one from the deeper mid basin, which is about 5,000 years old.
Scientists found 3,507 unique gene sequences – a stunning number for Lake Vostok – in about 500 milliliters of water taken from the ice cores. About 90 percent of the sequences came from the older, southwestern region, which is shallower and thought to be friendlier to life. The researchers were then able to make taxonomic classifications for about half of those sequences using the public gene bank.
Biologists divide all living things into three domains: bacteria, a type of single-cell microbe called archaea, and complex organisms called eukaryotes. The majority (94 percent) of the identified material was matched to bacteria. Six percent of the sequences matched to eukaryotes, a few of which were multicellular and were unprecedented finds for the hostile lake environment. Two sequences were from archaea.