NASA Arsenic Finding Questioned [CBC News]
A Canadian microbiologist is questioning a NASA-funded scientist’s discovery of a microbe that can use arsenic to form some of the basic building blocks of life as we know it, according to the CBC News in Canada. NASA said the peer-reviewed finding, published in the journal Science, raises the possibility that life could exist in environments previously thought to be unable to support it.
But Rosie Redfield, a professor with the University of British Columbia, effectively dismissed the finding as junk science. In a blog posting, Redfield suggested the finding could be the work of bad scientists or the result of a NASA agenda to promote the idea that life exists in places other than Earth.
“In an interview Monday, Redfield said the methods used by the researchers were so crude that any arsenic they detected was likely from contamination. There is no indication that the researchers purified the DNA to remove arsenic that might have been sticking to the outside of the DNA or the gel the DNA was embedded in, she added. Normally, purifying the DNA is a standard step, Redfield said: ‘It’s a kit, it costs $2, it takes 10 minutes.’
“She also questioned why the researchers analyzed the DNA while it was still in the gel, making the results more difficult to interpret: ‘No molecular biologist would ever do that.’
“Redfield also disagreed with the paper’s conclusion that the bacteria had to rely on arsenic to build molecules such as DNA because there wasn’t enough phosphate (a form of phosphorus) available in the samples with the lowest levels. Her arithmetic showed that in fact, there was enough phosphate to account for the amount of bacteria that grew.”