Michelle Laughran



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Debate on arsenic-based lifeforms

This was a fascinating talk, but there seems to be a significant amount of scientific debate potentially questioning these findings (via http://bit.ly/eedlhG). What do TEDsters think about it, I wondered...

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    Mar 16 2011: Great link, Michelle!

    I remember reading the article on the discovery of these alleged arsenic-based lifeforms on WIRED back in December, but I never encountered anything on the doubts surrounding it afterwards.

    Now that I've seen all the other articles I'm very disappointed that TED invited Mrs. Wolfe-Simon to give this talk before the matter had been scientifically cleared up.
    After reading a couple of articles detailing why these experiments are actually just "bad science" I too have to agree that it sounds like NASA's attempt to get a sensationalist story out there. And a release by press conference followed by a request for criticism only within scientific literature sounds very hypocritical...
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    Mar 12 2011: Is there an actual talk on the subject here, on TED? I'm interested to watch it if there is.

    I heard about the arsenic tolerant bacteria. I would say that it's certainly not impossible, Arsenic has similar electron arrangement as phosphorus and I remember when it was posited that silicon based lifeforms could exist because silicon has similar electron arrangement to carbon.

    The question is why is arsenic so scarce in most other organisms on earth? Why does phospate tend to occupy most DNA out there instead? One reason could be that arsenic is a poison to most living organisms but these bacteria are obviously not affected therefore such an organism could incorporate arsenic in the DNA molecule. Maybe it can incorporate both, phosphorus based oxides and arsenic based oxides.
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      Mar 16 2011: Not quite yet, however Felisa Wolfe-Simon's talk on this subject from TED2011 should be published on the site sometime soon.