Carl Sagan famously said, "Extraordinary claims require extraordinary evidence." So you could have predicted that when Felisa Wolfe-Simon and her team made an extraordinary claim -- that they had found a bacterium in a California lake that could be made to thrive on arsenic -- a lot of smart scientists would question her evidence.
It has been a week now since Wolfe-Simon published her findings in the journal Science. The paper, say scientists, is important -- if its conclusions are accurate -- because it broadens the definition of life as we know it, and means NASA's search for life beyond earth may need to broaden as well.
It became an online sensation before its release, partly because of a cryptic NASA news release promising "an astrobiology finding that will impact the search for evidence of extraterrestrial life." The blogosphere has quieted down (microbes from California are less sexy than microbes on Mars), but some biologists still are on fire.
Rosie Redfield of the University of British Columbia in Canada wrote her own blog post: "Basically, it doesn't present ANY convincing evidence that arsenic has been incorporated into DNA (or any other biological molecule)."
Redfield accused the Wolfe-Simon team of sloppy lab work and -- perhaps worse -- work you would only really do if you were trying to prove your findings, not test them to make sure they're right.
"Bottom line: Lots of flim-flam, but very little reliable information," she wrote. "I don't know whether the authors are just bad scientists or whether they're unscrupulously pushing NASA's 'There's life in outer space!' agenda." Redfield is one of several scientists who now have sent letters to the editors of Science.
Of course, this is part of the regular give-and-take of scientific research: You publish your work specifically so that other researchers either can contradict it or, if they confirm it, expand on it. There is another saying in science, less frequently quoted than Sagan's: "Break it or break it in."
But several scientists contacted by ABC News and other organizations have said last week's paper should not have been cleared by the reviewers assembled by Science to approve it for publication.
Many comments were like this one from Pat Heslop-Harrison of the University of Leicester in England: "I rather hope the paper is pulled pending more quality data. I can't see how this made it past any reviewers."
Redfield, in a telephone interview, went so far as to say it could do Wolfe-Simon damage.
"Because she's junior, she could rescue her career by using the good science that's required now," said Redfield.
Alien Life? Scientists Question Arsenic Research
Wolfe-Simon, who works for the U.S. Geological Survey and had funding from NASA, did not immediately respond to messages from ABC News. And several people at Science and NASA said they had not heard from her since the paper's publication. She did post a statement that said, in part:
"Our manuscript was thoroughly reviewed and accepted for publication by Science; we presented our data and results and drew our conclusions based on what we showed. But we welcome lively debate since we recognize that scholarly discourse moves science forward."
Redfield, for one, conceded that Wolfe-Simon is in a difficult position. Among other things, she is a young woman researcher in a field dominated by older men.
"As a woman in science, it is harder -- it is definitely harder," said Redfield. (Note added later: Dr. Redfield later posted an e-mail she said she sent to Dr. Wolfe-Simon: "...what matters in science isn't whether we make mistakes (we all do) but how we deal with them, and that I think you're handling the situation well.")
Does this mean the research team was wrong? Not necessarily, at all. There have been other papers in recent years reporting the possibility of life that uses arsenic, and scientists, debating what life on other worlds might be like, long have argued that it need not resemble life on earth.
Meanwhile, a spirited debate has broken out over the paper in Science, and even its detractors say that's healthy.
"This is great," said Redfield. "It is really fun to go through data and say, 'Where does this take us?'"