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Methane-Eating Bacteria May Presage ET Life
asukasoryu sends along an intriguing piece in light of our recent discussion of possible signs of life on Saturn's moon Titan. "Researchers have discovered that methane-eating bacteria survive in a unique spring located on Axel Heiberg Island in Canada's extreme north. The subzero water is so salty that it doesn't freeze despite the cold, and it has no consumable oxygen in it. There are, however, big bubbles of methane that come to the surface. Lyle Whyte, McGill University microbiologist, explains that the so-called Lost Hammer spring supports microbial life, that the spring is similar to possible past or present springs on Mars, and that therefore they too could support life."
Well, that's the Big Question, isn't it? While it is becoming clear that life can move from an enormously productive biosphere into ecological niches previously thought to be completely inhospitable to life, can it arise in such 'hostile' environments? TFA didn't really go into detail as to the biochemical characterization of the methanogenic critters. Likely that will happen sometime down the line and will be really interesting.
But we're going to have to get our respective asses to Mars if we really want to answer the question.
Faster! Faster! Faster would be better!
Organisms on Earth which live in extreme environments probably evolved from related species which live in less extreme environments. I have no doubt that there are Terrestrial organisms which could survive in certain environments on Mars, but if they have counterparts on Mars, where did they come from? If they evolved on Mars, there has to have been an environment in which such evolution could have taken place over some kind of condition gradient, from less hostile to more hostile. If they came from Earth, you need a hell of a story about how they got there -- not only are meteor strike ejecta a lot less likely to make it from Earth to Mars than the reverse, you have to envision one piece of rock that just happened to be carrying a viable population of (already rare, even here on Earth) extremophiles that were suited for certain (also very rare) Martian conditions, and landed in just the right place.
If we can ever confirm that Mars had a more life-friendly environment for a significant portion of its history, of course, then these objections can be disregarded. But until we have much more evidence of that than we currently do, I'd be very surprised to find native life on Mars. It's much more likely that if anything is living there, it was carried there by probes from Earth -- and even that seems like a one in a million shot.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
Life finds a way, ladies and gents.
We don't know that. We know that once life gets going it seems to be very resilient and manages to find a lot of different environments to colonize. But we don't know how easy it is for life to start. If life starting is really difficult, then it may be that Titan and Mars are completely barren. What this sort of thing does mean is that if there ever was life on Mars, there's a decent chance that there's still some.