For the past several weeks we've been anxiously awaiting news from the Russian research team that recently drilled into Lake Vostok, a massive body of water that's located about 2 miles below the Antarctic surface — and possibly cut off from the world for millions of years. Now, according to Russian news site RIA Novosti, a preliminary examination of water samples has uncovered bacterial DNA that doesn't appear to belong to any known subkingdom. The researchers are calling it "unidentified" and "unclassified" life.
The research team, which includes Sergei Bulat from the Laboratory of Eukaryote Genetics at the St. Petersburg Nuclear Physics Institute, cautions that tests are still ongoing, but that they're "unlikely to disprove the results."
The samples were extracted this past January 10th from a depth of 3,600 meters.
RIA Novosti writes:
"After excluding all known contaminants…we discovered bacterial DNA that does not match any known species listed in global databanks. We call it unidentified and 'unclassified' life," Bulat said.
Seven samples of the same species of bacteria were found in water frozen on the head of the drill that was used in 2012 to reach the lake, covered by a 3.5-kilometer-thick ice sheet, but the match between its DNA and any known organisms never exceeded 86 percent, while a match of under 90 percent is already enough to indicate a new species, Bulat said.
Attempts to build a phylogenetic tree for the newly discovered microorganism, which indicates a species' evolutionary relationship to other species, showed that the Antarctic bacterium did not fit any of the main categories of microorganisms in its taxonomic domain.
"If it were found on Mars, people would call it Martian DNA. But this is DNA from Earth," Bulat said.
Writing in SciAm, Caleb Scharf expresses some cautious optimism:
While the technical details are not yet available it seems that when the scientists...compared this DNA to a database of known species they found no clear match. The closest they could come was about 86% similarity, which is far enough off to suggest a new species.
Obviously we'll need to wait to see the details. Phrases like ‘bacterial DNA' are pretty vague – are they looking at things like the ubiquitous 16s rRNA, or some other sequence selections typically used for metagenomic analysis? Do they have cells under a microscope?
It looks to be exciting news though. Decades of hard work to reach one of the most alien places on Earth may actually be revealing lifeforms we have not knowingly encountered before. It doesn't really get better than this!
We'll keep you posted as new information emerges.