By Tyson McVicar on Quarks to Quasars
Lake Vostok: Life in one of the most Inhospitable Places on Earth:
Credit: Nicolle Rager-Fuller / NSF
The lake presents itself as an analog for the study of both extremophilic microbial life (and possibly larger organisms) and evolutionary isolation. This inhospitable environment parallels some environments that we think might exist elsewhere in the solar system – either in the subsurface of Mars or on icy moons like Enceladus or even Europa. Ultimately, the search for life on other planets could start here on Earth at Lake Vostok.
Drilling is restricted to 3590 meters (2.2 miles) below the surface ice (just a few hundred meters above the lake) as the lake itself is considered inaccessible due to fears of contamination. A number of scientists have examined ice cores taken from above the lake, focusing on the so-called “accretion ice” at the base of these cores. Accretion ice was once lake water that later froze and adhered to the overlying ice sheet—and what’s in that ice might therefore provide clues to what’s in the lake itself.
Lake Vostok has made news again because of its most recent published findings shared recently in PLOS ONE. Scientists led by Yury Shtarkman, a postdoc at Bowling Green State University in Ohio, identified a startlingly diverse array of microbes in the accretion ice—the most diverse suggested yet.
By cultivating and sequencing nucleic acids found in the ice, they identified more than 3500 unique genetic sequences (mostly from bacteria, but there were some multicellular eukaryotes). And those were similar to those of creatures found in all sorts of habitats on the planet: lakes, marine environments, deep-sea sediments, thermal vents, and, of course, icy environments.
Overall, researchers have generally observed low concentrations of such microbes relative to most environments on Earth. But they found the POTENTIAL for a complex microbial ecosystem of bacteria and fungi, and genetic sequences from crustaceans, mollusks, sea anemones, and fish. Note that Lake Vostok was in contact with the atmosphere millions of years ago, so a complex network of organisms likely populated the lake during that time. The team also found bacteria sequences that are common symbionts (organisms that live in symbiosis of each other) of larger species. There could be the poFEussibility of distinct ecological zones. As they are just studying accretion ice, the idea of fish actually living in the lake remains unclear.
Either way, this lake is far from being devoid of life. This does not conclusively lead us to the conclusion that life exists on other planets and moons in our solar system. But if abiogenesis is correct (still repudiated, but evidence is starting to suggest it is), it makes the case that much stronger for those seeking life beyond our planet.
Radar satellite image of Lake Vostok (Credit: NASA)
Lake Vostok has made news again because of its most recent published findings shared recently in PLOS ONE. Scientists led by Yury Shtarkman, a postdoc at Bowling Green State University in Ohio, identified a startlingly diverse array of microbes in the accretion ice—the most diverse suggested yet.
By cultivating and sequencing nucleic acids found in the ice, they identified more than 3500 unique genetic sequences (mostly from bacteria, but there were some multicellular eukaryotes). And those were similar to those of creatures found in all sorts of habitats on the planet: lakes, marine environments, deep-sea sediments, thermal vents, and, of course, icy environments.
Overall, researchers have generally observed low concentrations of such microbes relative to most environments on Earth. But they found the POTENTIAL for a complex microbial ecosystem of bacteria and fungi, and genetic sequences from crustaceans, mollusks, sea anemones, and fish. Note that Lake Vostok was in contact with the atmosphere millions of years ago, so a complex network of organisms likely populated the lake during that time. The team also found bacteria sequences that are common symbionts (organisms that live in symbiosis of each other) of larger species. There could be the poFEussibility of distinct ecological zones. As they are just studying accretion ice, the idea of fish actually living in the lake remains unclear.
A scientist traversing above the ice miles above the ice of Lake Vostok (Credit: M. Studinger, 2001)
Either way, this lake is far from being devoid of life. This does not conclusively lead us to the conclusion that life exists on other planets and moons in our solar system. But if abiogenesis is correct (still repudiated, but evidence is starting to suggest it is), it makes the case that much stronger for those seeking life beyond our planet.
