Scientists are all in a tizzy over the so-called arsenic-based bacteria NASA claims to have found in California’s Mono Lake (which Sara B. briefed us on earlier in the week), and those of us hoping for reassurance that we are not alone may have to take comfort in our well-worn E.T. VHS and our Aliens versus Predator comics. It would appear, based on the criticism of well-known biologists in America and Canada, that several flaws undermine the validity of the study, which is unlikely to stand the test of time and further exploration.
PopSci has a fairly approachable article about the whole debacle, outlining the three biggest concerns raised regarding how Felisa Wolfe-Simon and her associates conducted their study.
First, it was pointed out that the environment the scientists created in minimizing phosphorus and keeping the bacteria awash in arsenic is unnatural and unlikely to occur outside a controlled setting.
Second, claims that the bacteria incorporated arsenic into their DNA are being disputed on the basis that arsenic is water-soluble, meaning bacteria with arsenate DNA should have fallen apart when washed in water. They didn’t, leading to point three.
Third, though the NASA scientists claim that the amount of phosphorus in the bacteria was so minute as to not account for any of its growth, biologists have disputed that claim, pointing out that the bacteria may have learned to metabolize smaller amounts of phosphorus (which would explain the non-dissolving DNA, as phosphorus is not water-soluble) just as easily as they could have replaced an entire building block of life with arsenic.
Bill Nye the Science Guy has yet to comment, but we’re calling this one. It was a well-intentioned, accidental hoax. If you need me, I’ll be in the corner, quietly whistling the X-Files theme song.