This is interesting. There's a new piece by Carl Zimmer on Slate.com on those bacteria that supposedly can grow on arsenate instead of phosphate (see my post here), and it's not a friendly piece. It's called "This paper should not have been published." That kind of gives away the punchline, doesn't it? They quote a lot of microbiologists who are extremely critical of the work. You can read a detailed critique at Rosie Redfield's blog:
Arsenic-associated bacteria (NASA's claims)
Rosie makes a lot of good points, leaving me quite skeptical of the original paper.
In the Slate piece, Zimmer compares this overhyped NASA announcement to the overhyped NASA announcement about alleged bacterial fossils in Martian meteorite ALH 84001. The big difference is that the evidence for life on Mars was entirely inferential and open to interpretation. This alleged arseno-DNA, however, can be tested. Rigorously. That means we won't have to wait long for a definitive answer on this controversy.
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