Sunday, December 5, 2010

(Very) little green men

As promised, let's dork it up.

Last Thursday, NASA announced it had discovered a new form of life. This new beastie was not found on another planet, however, but right here on Earth, in California's Mono Lake.

That environment, while not extraterrestrial, is certainly interesting. The water contains tremendous amounts of arsenic, an element that normally acts as a poison on your basic Earthbound animal. The reason (and forgive me, Mrs. Howk, if I screw this up) is that literally EVERY BIT of known life on Earth is built from and operates using six elements: carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur. All are crucial. In human biology, for instance, phosphorus is an essential part of our energy-generating mechanism, fueled by ATP, or adenosine tri-phosphate.

But look just below phosphorus on a periodic table and you see arsenic. It is remarkably similar... but dissimilar in too many ways to simply substitute. In fact, the reason arsenic is so deadly is because the body mistakes it for phosphorus and tries to use it in normal metabolic processes, which doesn't work.

Until now.

This new microbe can use arsenic to survive. Here's how one of the scientists put it:

“These data show that we are getting substitution across the board,” said Dr. Felisa Wolfe-Simon. “This microbe, if we are correct, has solved the challenge of being alive in a different way.”

Tiny bug, big discovery.

And what THAT means is a) all life did not necessarily evolve from a common ancestor, i.e. there were, at some point, at least two separate "tracks" viable life was taking, and b) we now have a lot more environments off our planets in which we could conceivably find life.

How cool is that?

So although NASA didn't trot out E.T., a Gray or, heaven forbid, something out of a Ridley Scott movie, it's still an exciting discovery. Here's to more big announcements. I can't wait to blog about faster-than-light travel and aliens made of silica-arsenate.

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