Arsenic and Old Life Forms

A year or so ago a NASA chemist named Felisa Wolfe-Simon, then at NASA's Astrobiology Institute in Menlo Park, California, stirred controversy in the scientific world with claims that she had coaxed bacteria from an arsenic-rich lake in California to swap the usual phosphorus in their DNA for toxic arsenic. The discovery that living organisms could function and thrive on arsenic rather than phosphorous had lots of implications, including implications for origin of life scenarios. Apparently life was more flexible than previously surmised and this might make abiogenesis easier to accomplish than had been thought.

Well, perhaps not. Like so many discoveries having to do with the origin of life and evolution it turns out that Ms Wolfe-Simon's work has fallen under a pall. It can't be duplicated by other researchers.

The New Scientist reports that:

... after trying to grow the same strain of bacteria in a soup containing arsenic, other researchers have failed to repeat the findings. "To the limit of what our spectrometer will detect, there's no arsenic in the DNA," says Rosie Redfield of the University of British Columbia in Vancouver, Canada, who posted her results to a blog this week.

Wolfe-Simon has defended her original results and is continuing to analyse her lab-grown bacteria at the Lawrence Berkeley National Laboratory. "As far as we know, all the data in our paper still stand," she told New Scientist. "We shall certainly know much more by next year."

Perhaps she'll be vindicated, but it's still true that whether it's microfossils of bacteria found in meteorites, or primitive ape-men, or alleged vestigial structures, or a host of other finds that subsequently turn out to have been mistakenly advertised as confirmations of darwinian evolution, it seems as though eagerness to make a breakthrough leads to an awful lot of damaged scientific reputations.