Last week, NASA researchers announced the discovery
of a bacterium containing arsenic-based DNA in California's Mono Lake.
(All other forms of life use phosphorous instead.) Published in Science
magazine, the results prompted immediate speculation about it whether it would affect the search for life on earth and beyond. One week later, both the
results and the way they were presented to the public is drawing scrutiny.
A sampling of opinions from around the web:
- Premature Scientific American's Alla Katsnelson says the findings NASA released last week were incomplete and at times contradictory. Dubious to begin with, the results of the study were "communicated to non-specialists" in a slapdash manner that suggested a "new chemistry of life" had been discovered, a claim that was "at best premature." Katsnelson notes the study fails to identify any compounds containing arsenic, a glaring oversight considering "the team could have directly confirmed or disproved the presence of arsenic in the DNA or RNA using targeted mass spectrometry." The researchers also ignore indications in their own data that, rather than building biomolecules, the bacteria is "simply absorbing and isolating arsenate while making use of the trace phosphates in its environments."
- Very Flawed The existence of arsenic-based life is far from impossible, but the study's sloppy methodology taints these results, writes Carl Zimmer at Slate. Zimmer blames the researchers for failing to take "basic precautions to avoid misleading results ... when the NASA scientists took the DNA out of the bacteria, for example, they ought to have taken extra steps to wash away any other kinds of molecules. Without these precautions, arsenic could have simply glommed to the DNA, like gum on a shoe."
- Nonsense University of British Columbia microbiology professor Rosie Redfield eviscerates the paper in a detailed review posted to her research blog. "Basically," she writes, "[the paper] doesn't present ANY convincing evidence that arsenic has been incorporated into DNA (or any other biological molecule)." What it does offer is "lots of flim-flam ... if this data was presented by a PhD student at their committee meeting, I'd send them back to the bench to do more cleanup and controls."
- Media's Fault Discover's Jennifer Welsh blames the press for misrepresenting the nature of the study. The results--assuming they hold up to further scrutiny--are "amazing and definitely shed new light search for life in extreme (even extraterrestrial) environment," but don't represent a meaningful breakthrough in the search for extraterrestrial life. The bacteria in question isn't alien--it's from California. Despite "the build up, the early embargo break, and a long press conference," many media outlets still missed the distinction.
- Plenty Of Blame The Guardian's Martin Robbins observes that when a story is this thoroughly botched by all parties involved, it is difficult--and maybe even pointless--to play the blame game. Better instead, Robbins suggests, to treat the whole thing as a cautionary tale, "a story of everything that's wrong about the relationship between science, peer review, the world of publishing, and the mainstream and independent branches of the media in 2010."