Thursday, December 2, 2010

The Arsenic Factor

Some citizens are astonishingly blasé about it, but the announcement made today by NASA is nothing short of explosive. A new form of bacteria discovered in California's Mono Lake - called GFAJ-1 - has a different DNA structure than any life form ever known to exist on Earth, and ever thought possible.

This new form of bacteria replaces phosphorus at the DNA level with arsenic, and as C-Net notes:

That would distinguish it from every other form of life known to man, all of which, no matter how diverse, is comprised of the same six elements, phosphorus, sulfur, carbon, hydrogen, oxygen, and nitrogen. But the bacteria found in Mono Lake--which is known for its unusual chemistry, including very high levels of salinity, alkalinity, and arsenic--is made partly of arsenic, and has no phosphorus in its DNA.

This puts a new slant on everything.

Now that we can throw out the long-held tenet that all life in the Universe is made of the same six components, we have to start all over again in our examination of planets, exoplanets, moons, asteroids, comets and what-have-you, and reassess the possibility of life on them. Jupiter, for example, has an abundance of arsenic in its composition. Until today, the official scientific party line would have been that life as we know it could never exist there. And now, it could be possible that something like GFAJ-1 could thrive in pockets of Jovian arsenic.

And it doesn't stop at arsenic. The floodgates are open now to argue that other combinations of elements could conceivably make up new kinds of DNA that most scientists hadn't even imagined until now. (Of course, Star Trek had it right back in 1966 when they posited life based on other elements instead of carbon.)

My question is, how did this bizarre new bacteria manage to survive in Mono Lake without being noticed up till now? Is the possibility not a large one that it got here extraterrestrially via a meteorite or something?

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