‘Weird life’ reveals science at work

Henry Bortman

Astrobiology researcher Felisa Wolfe-Simon works with samples at California’s Mono Lake.

The continuing controversy surrounding the announcement of strange bacteria deep in a California lake that can apparently survive on arsenic and even incorporate the element into its DNA is being held up as a shining example for how the scientific process works.

The latest to point this out are the folks at Real Climate, a blog on climate science — a discipline that is no stranger to controversy.

The arsenic-DNA study, published in the journal Science, was announced at a NASA news conference on Dec. 2 that was hyped in advance as an opportunity “to discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life.”

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What’s groundbreaking about the find is it suggested that salt-loving bacteria gathered from California’s Mono Lake could be coaxed to substitute atoms of arsenic, which is toxic to life on Earth, in place of the usual phosphorus atoms in DNA and other parts of their cellular machinery.

If that’s possible on Earth, then it’s also possible that such alternate forms of life could be thriving elsewhere in the universe. This, in turn, might expand the definition of “life” and require a broadened search for extraterrestrial organisms.

Since the study was published, a number of microbiologists and chemists have questioned whether the experiments actually proved the researchers’ point.

Among their criticisms are concerns that inadequate care was taken in purifying DNA samples from the bacteria in the arsenic-rich medium, and that the arsenic found in the DNA was merely contamination. They said that the bacteria might have been using trace amounts of phosphorus left as impurities in the growth medium.

As these criticisms played out in the media and on the Internet, the researchers behind the original paper issued a statement responding to their critics — and said more would be forthcoming in Science.

So that’s the story so far. Has this high-profile airing of claims, counterclaims and counter-counterclaims hurt the credibility of the scientists involved? Not at all, Real Climate’s bloggers say. Instead, they contend that the controversy “has demonstrated the credibility of scientists, and should promote public confidence in the scientific establishment.”

Climate scientists are keen to point out the scientific process at work, in part to counter their own critics. Such critics say many researchers are afraid to go against the scientific consensus that human activity is a driving factor in global climate change because it might staunch their flow of funding from agencies such as NASA.

Real Climate flagged a comment on the Watts Up With That blog, a hub of climate skeptics, that reads:

> “It’s amazing how fast the scientific community came out to attack NASA for what they claim is plainly flawed science. Then again, NASA isn’t funding any of the attackers. > > “In the Climategate mess, however, we still have heard very little from an awful lot of so-called scientists who should have been saying a lot more about flawed science but are too afraid to lose their grant money.”

The reality is more complex: Science writer Carl Zimmer has done the work to show that many of the arsenic-DNA study’s critics are indeed NASA-funded, including Norman Pace at the University of Colorado, extremophile expert Hazel Barton at the University of Northern Kentucky, and John Roth at the University of California at Davis.

Real Climate notes: “Scientists offer opinions based on their scientific knowledge and a critical interpretation of data. Scientists willingly critique what they think might be flawed or unsubstantiated science, because their credibility — not their funding — is on the line.”

While the Real Climate bloggers have mixed feelings about the arsenic-DNA controversy playing out in the blogosphere and media, rather than strictly within the confines of the peer-review process, they are far from alone in using the controversy to help explain the merits of the scientific process.

Over on the NeuroLogica Blog, for example, Steven Novella has a post up that responds to a comment on the ScienceNOW website in which the criticism is characterized as “unfair.”

> “The commenter is confusing being fair with being nice. The self-critical aspect of science is not nice. It’s brutal – necessarily so. But it is still fair and professional, just not politically correct. > > “This is one critical aspect of science that I feel the public needs to better appreciate. This is also a fun and dramatic aspect of science — real-world mud fights where scientists go at each other’s throats. The mass media needs to appreciate this real drama more so that they will rely on their hackneyed Hollywood cartoon of science less.”

In USA Today, science columnist Dan Vergano recaps the controversy and notes that the back-and-forth is likely to continue, though it will eventually be settled via the peer-review process.

What do you think about the way in which the “weird life” controversy has been playing out on blogs and in the media, rather than strictly through the peer-review process? Is it actually a shining example of science at work? Feel free to weigh in with your comments below.

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John Roach is a contributing writer for msnbc.com. Connect with the Cosmic Log community by hitting the “like” button on the Cosmic Log Facebook page or following msnbc.com’s science editor, Alan Boyle, on Twitter (@b0yle).

URL: http://cosmiclog.msnbc.msn.com/_news/2010/12/29/5733384-weird-life-reveals-science-at-work

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