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View Full Version : Extremophile Hunt Begins in Antarctica, Implications for Exobiologists



Fraser
2008-Feb-09, 03:50 AM
An expedition has set off for Antarctica's Lake Untersee in the quest to find bacteria living in one of the most extreme environments on Earth. The bacteria-hunting team are looking for a basic lifeform in a highly toxic location. Resembling the chemistry of Mars, moons of Jupiter and Saturn, even comets, the ice-covered lake may [...]

More... (http://www.universetoday.com/2008/02/08/extremophile-hunt-begins-in-antarctica-implications-for-exobiologists/)

Ronald Brak
2008-Feb-09, 05:06 AM
This sentence in the article is kind of iffy:


Some bacteria are content to be frozen for over 30,000 years before they are thawed to continue life as if nothing had happened.

I call reports of ancient bacteria being revived like this pre-clover bacteria. Can't say it's impossible, but it only takes contamination by one bacterium to give an apparently positive result and no one ever hears about the studies showing negative results.

Lil Grasshoppah
2008-Feb-09, 12:42 PM
I think this test has been replicated enough to warrant some credibility. If I recall, the "resurrected" bacteria are more sluggish (in reproduction, for instance) than similar, more modern counterparts, but otherwise appear to be functioning normally.

The problem of the positive reporting bias is a common issue for statistical studies (although more for pseudoscience folks who like to fail to report all the times that, say, a psychic blew a prediction), although not really a valid issue here. Nobody is trying to claim that all bacteria from 30,000 years ago can be revived - just that it can be done. Nothing less exciting in the news than "50 more exciting scientific experiments yesterday showed absolutely no positive results at all."

Ronald Brak
2008-Feb-09, 08:04 PM
I haven't looked into this enough to arrive at strong conclusions, but I still feel skeptical, which probably isn't a bad thing. Thirty thousand years actually isn't so long, but there are other claims of reviving bacteria that are millions of years old that seem much less likely. I'm not sure how they distinguish between bacteria that have been dead (inactive) all that time and those that have been living an extremely sluggish low energy life which would still enable them to repair their DNA.