It found that the bacterium was not really replacing phosphorus with arsenic throughout its DNA but “may sometimes assimilate arsenate into some small molecules in place of phosphate.”
Rather than being a new form of life that thrives on arsenic, Science’s statement summed up the latest studies by describing the bacterium as “a well-adapted extremophile that lives in a high-arsenic environment.”
They did not, however, retract the original paper.
Why this matters:
1) NASA was using its prestige to attempt to shut down discussion (snipes about dissenting scientists being mere bloggers are a clue. Today lots of people blog, whether or not they live in pajamas or eat cat food.).
2) More important, when looking for extraterrestrial life, we first need to answer a key question: Is life constrained? Will only certain formulas work? If so, can laws be derived, to prevent wastes of time? To judge from the uproar around super-Earths, it’s early days right now.
Hat tip: Pos-Darwinista