Meanwhile, scientists are still debating arsenic-based life

Scientists don't get bored with a question just because the press does. Last December, research claiming to have found evidence of "arsenic-based life" on Earth touched off a firestorm of controversy, as many scientists weighed in, via blogs and magazines, on why they thought the research, and its conclusions, were flawed.

Last week, the debate moved into traditional science media, as the journal Science, which published the arsenic life paper, published eight critiques of it, as well as a response to the critiques by the authors of the original paper. One of the critiques was written by Rosie Redfield, a microbiologist who was also one of the first scientists to post a critique of arsenic life in blog form.

These critiques don't completely end the debate. The original researchers recently released their ostensibly arsenic-based bacteria to other scientists, who will now try to replicate the results. But the critiques have changed the discussion in some subtle, and important, ways. For instance, New Scientist and The Washington Post pointed out that, in responding to the critiques, the original researchers have changed their conclusions from having found "proof" to having produced a "viable interpretation." In other words, they haven't backed down, but they have copped to being less certain.