Arsenic Bacteria: Bad Science Gets Outed, Slowly

In previous posts, I've argued that science is different from religion partly because it's a collaborative effort and allows scientists to correct each others' errors, falsehoods, and episodes of self-deception. Unfortunately, that self-correction doesn't always translate into the public understanding of science right away. The so-called arsenic-based life announcement was a perfect example.

in December 2010, NASA promoted a so-called arsenic-based life form as one of the most important discoveries of all time. A muddled, overblown press conference hinted at the absurd idea that this was part of some new tree of life, represented a "shadow biosphere", and had some relevance to the search for life elsewhere in the universe. It was obvious after 15 minutes of this circus that they were making much out of nothing. Even more annoying, most of the press and blogosphere bought into it.

(I didn't yet write this blog when the news broke, but I wrote two debunking stories for the paper and then revisited the issue in the context of origin-of-life studies in June in this column.)

A scientific paper made the somewhat less hyperbolic claim that some of the phosphorus in the organism's DNA was being replaced by arsenic. Lead researcher Felisa Wolfe-Simon has publicly stood by this while backing off more her outrageous press conference claims. Even the paper, however, is almost certainly wrong. Several biologists who study heavy metals and microbes told me back in Dec. 2010 that the paper never presented proper evidence that arsenic was in the DNA. Since then, biologist Rosie Redfield has tried to reproduce the experiment, and shown that no arsenic incorporates itself into the organism's DNA. Here's the latest on the fiasco from Science News:

"Wolfe-Simon, who says she can't comment in detail until Redfield's results appear in a peer-reviewed journal, wrote in an email that her original paper never actually claimed that arsenate was being incorporated in GFAJ-1's DNA, but that others had jumped to that conclusion. "As far as we know, all the data in our paper still stand," she wrote. "Yet, it may take some time to accurately establish where the [arsenic] ends up."

GFAJ-1, by the way, is the cute name Felisa-Wolf Simon gave her bacteria. It stands for "give Felisa a job". I listened to the press conference, which still on YouTube or such media outlets. Wolfe-Simon said in front of an international audience that that arsenic atoms had been taken up by the DNA. NASA even showed a colorful animated cartoon to illustrate this. What were they thinking?

Other organisms have withstood higher concentrations of arsenic. If GFAJ-1 hasn't replaced phosphorus in the DNA, there's no reason people should care, let alone be told by NASA that this organism is somehow different from known life. In the biology community, it's already defunct and Dr. Redfield is playing a crucial role - one that's essential for science to progress toward truth.