Thursday, December 2, 2010

Arsenic-Munching Bugs

Photo courtesy NASA

So it’s bacteria that metabolize poison.

And not on Mars, Rhea, or Titan, but teeming – some of them with tentacles so they can teem more efficiently – in California’s Mono Lake.

What’s significant is that this is more than bacteria using arsenic compounds instead of water in photosynthesis, this is bacteria using arsenic rather than phosphorous to build themselves.

Phosphorous, per Science Daily, is one of the building blocks of DNA and RNA. Arsenic, which is chemically similar to phosphate, is toxic to some life forms because it takes the place of phosphorous. Apparently, these bacteria have learned to adapt to that substitution.

Sez Science Daily:
“The idea of alternative biochemistries for life is common in science fiction,” said Carl Pilcher, director of the NASA Astrobiology Institute at the agency's Ames Research Center in Moffett Field, Calif. “Until now a life form using arsenic as a building block was only theoretical, but now we know such life exists in Mono Lake.”
Plenty damn cool. Kinda Andromeda Strain cool and creepy as well, and certainly fodder for new science fiction stories waiting to be written: They came! They farted! We all died of arsenic poisoning!

Now scientists can consider celestial bodies where arsenic is plentiful as potential cradles of life, not necessarily clouds of doom for life. What Jeff Goldblum’s character in Jurassic park says, indeed, is true: Life finds a way.

And why is that really shocking? Frankly, I expect there to be life on other worlds. In this infinite universe of ours, our puny planet – and our incomplete understanding of the conditions conducive to life – cant’ be the summum bonum of all that’s out there. It’s nice to know that we’ve got a different set of conditions to consider.

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