The arsenic post I never wrote

I never wrote what I meant to here – I simply could not keep up with the rest of the blogs regarding arsenic life!  But I’m also aware that outside of the sci-twitter bubble, what went down may not be entirely clear, so here’s the beginning of the draft just in case you need to catch up.

Reactions to NASA’s announcement of “arsenic-based life” have been resounding through the science world these past few weeks.  (For more thorough reviews, check out Bora Zivkovic’s link dump, Martin Robbins’s coverage, or the National Association of Science Writers.)  For those who haven’t been scouring all the blogs, I’ve illustrated a brief review of events.

The saga began with a NASA press release announcing  a press conference about a discovery about “an astrobiology finding that will impact the search for evidence of extraterrestrial life.”  This led to speculation about aliens – life on Titan? – and then, when it was uncovered that the study was written by scientists studying the arsenic-rich Mono Lake in California, perhaps the researchers discovered a “shadow biosphere” – a form of life unlike ours, based on different molecules and evidence of a novel evolution of life on earth.

The actual paper, published in Science, instead announced that the scientists had found a bacterium that, when forced in a lab, could utilize arsenic in place of phosphorus in its molecules, including DNA.  After the hype and build-up, it was a disappointing announcement.  Due to the massive let-down, a lot of writers and scientists (myself included) chose to accept these findings instead of scrutinizing them.  It is a bit embarrassing in hindsight, but after so much hype about a scientific discovery that engaged the public, I wanted to find something to stay excited about, if only to support the idea that science isn’t a complete sham.

Soon after, scientists began to carefully look at the researchers’ methods and found that these findings simply weren’t very well-supported.  For the details, I recommend Rosie Redfield’s highly-publicized critique as well as Alex Bradley’s on We Beasties.  The researchers’ evidence could easily have been contaminated, and they failed to do some fairly simple tests to definitively show the use of arsenic by these microbes.  At this point, most media sources threw up their hands in frustration and stopped covering the story.  (For more detail, see Carl Zimmer’s Slate piece, “This Paper Should Not Have Been Published.”)

This series of events led to some interesting reflections around the blogs, including thoughts on the peer review process, the scientific process, and the upside of public scientific debate.  The authors’ refusal to engage the bloggy criticisms (even though they used the web to get everyone hyped about their discovery) got everyone into an uproar as well, as described in this open-access Nature editorial.