Nasa news conference (re: Arsenic-based life form?)

PZ says It's not an arsenic-based life form:

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It's an extremophile bacterium that can be coaxed into substituting arsenic for phosphorus in some of its basic biochemistry.

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Much more at the source cite, including the info that arsenic is found right below phosphorus in the periodic table.MooseEdited by Minnemooseus, : Add PZ's topic title to the first sentence.

God forbid, I'm actually at least somewhat in agreement with you.I invite you to go to my old topic To fund or not to fund - Are some science projects worth pursuing?.Moose

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Professor, geology, Whatsamatta U
Evolution - Changes in the environment, caused by the interactions of the components of the environment.

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"Do not meddle in the affairs of cats, for they are subtle and will piss on your computer." - Bruce Graham

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"The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness." - John Kenneth Galbraith

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"Yesterday on Fox News, commentator Glenn Beck said that he believes President Obama is a racist. To be fair, every time you watch Glenn Beck, it does get a little easier to hate white people." - Conan O'Brien

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"I know a little about a lot of things, and a lot about a few things, but I'm highly ignorant about everything." - Moose

Larrry Moran says:

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For a start, even the title of the paper is misleading. The title says "A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus" but all of the data show that there was phosphorus in the media and that the bacteria used it for growth and reproduction. This selected strain of bacteria incorporated more arsenic than non-selected species but it by no means did it replace all phosphate with arsenic. Only a few percent (at most) of the phosphorus atoms in DNA, for example, were replaced by arsenic.

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He goes on to link to this more detailed review. I'll pull the following out of the cite, although I think PZ Myers more or less made the same observation in the link I previously cited:

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Under the microscope the bacteria grown with arsenate and no added phosphate (Fig. 1 C) look like plump little corn kernels, about 1 m across and 2 m long. They contain many structures (Fig. 1 E) which the authors think may be granules of the wax-like carbon/energy storage material polyhydroxybutyrate (PHB). Bacterial cells produce this when their carbon/energy supply is good but other nutrients needed for growth are in short supply. Cells grown with phospate and no added arsenate are thinner and lack the granules (Fig. 1 D)

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Much more gory detail at the source, but it sure seems to me that the bacteria were not "thriving" but rather were struggling to survive.Moose

Hey, I'm not even remotely a biologist (the closest I've ever come to a biology class was invertebrate paleontology) but I thought it a good thing to point out the opinions linked to in my previous message. But I had to throw something else in or be in violation of rule 5 (No bare links etc.). The "bolded" is my "not based of any personal expertise" impression. I must leave it to those who can handle the "gory details" of that second cite to pass a much more qualified judgment.Now, if you want to get into oddities in preCambrian geology, that's where I have a bit of personal expertise (but just a bit).Moose