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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."
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.
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).
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What gets me about all of this, scientists seem to be hell-bent on not believing that life could form with any other components that what is apart of life on this planet. This is a very narrow, and to an extent, very arrogant view point. Life finds a way, to quote "Jurrasic Park". Yes a very different matter all together, but the meaning remains the same. I for one hope that they are proven right.
Umm, Put a some infront of that because not all scientist think that way, its all about evidence, lack of evidence is not proof of such a thing being impossible.
Scientists are not "hell-bent on not believing" anything! Neither are they hell-bent on believing anything. If they were, they would ONLY be scientists in their own mind. The only thing true scientists are hell-bent on is asking questions and defining/quantifying the uncertainties assoicated with the answers they get to those questions. All science is, is a way of asking questions...nothing more. All of this public, media, and political overreaction to technical findings is disturbing when one understands the sad state of US education and politics.
Pirate, you are correct, if I could change that I would, I do appologize for that. Megaceryle, that was the point of my post, a true scientist worth his salt is going to wait for independant verification/disproval before come to a judgement on the matter. There is a difference between someone saying "I have my doubts this is correct but I must wait on further results" vs. "I think this is wrong because my data says this is not possible"
Eric,
Scientists have this annoying little habit of going with what they know, instead of latching onto every little crack-pot theory that's out there. It's not that they're not open to the idea that life may evolve differently in other environments or under different circumstances. It's just that they like to wait until there is some evidence that this is actually possible, before they start actively endorsing any alternate theories.
Ok read that line very clearly. The difference one, has their reservations, but is waiting verification, the other has already written it off as not possible, and doesn't care if someone else can prove right or wrong. To them it is not possible, and don't care if they are proven otherwise. I support the former, I denounce the latter. Like I said in a lower post, we are basing these view points on what we know to exsist soley on this planet, which is a very narrow view point, yes people have their reservations whether or not these findings are accurate, but at least they are willing to wait for independant verification. I am referring to the ones who are denouncing this, simply because it does not conform to life on this planet, and they are unwilling to accept that it may be possible that alternate forms of life can exsist. In a universe that is showing some of our past theories may be in accurate, or missing parts, we should at least entertain the possibility, but wait for verification, rather than simply say that its not possible just because it has not been proven, as that voids the final step in the scientific method.
In short, I am not railing against the ones who want verification, I am railing against the ones who refute the possibility all together, before we get further evidence for or against.
silly people humans cant create things only the gods can create things.... duh the bibles says so
It isn't arrogance. It's called "knowing things," and "extrapolating from what we know."
There are issues with the arsenic findings, and biochemists have valid reasons for questioning the results presented. For example, although phosphorus and arsenic have the same valence (meaning that hypothetically it can substitute for phosporus), arsenic atoms are larger, and that makes a difference in DNA. The phosphates have a long half-life in water, while the arsenates and arsenides don't. Since bacteria are necessarily aqueous--and we have reason to believe that water is a necessary medium, since life requires a certain spriteliness to its chemistry, and water is liquid at a useful temperature--DNA that falls apart after a few minutes isn't much good for life as we know it, or even as we don't know it. If a mechanism can be discovered that resolves the problems with arsenic-for-phosphorus substitutions in DNA, then we'll have learned something cool, and can look outward with a different perspective on how life chemistry works. Until then, there are serious questions to be asked and answered.
The funny thing is--and despite comforting movie cliches--life occupies a very narrow range of environmental and chemical possibilities, given the overall scope of what's available in the universe. We have yet to see any indications of life at all on other planets. (I'm not talking intelligent life--I mean, life at all.) The spectroscopic evidence would be copious and easily-discerned, if it was there. It hasn't been thus far.
Simulations run using ammonia in place of water don't produce anything that looks viable. (Inasmuch as we understand physics and chemistry--and we do so reasonably well at those levels--the numbers just don't crunch. Or even crisp.) There aren't any liquids I'm aware of that could function in place of water at higher temperatures.
Could life be solid and crystalline? It's harder to say "yes" than to say "no," because the mechanisms are so hard to hypothesize. Remember that the extremophile bacteria types are just that--bacteria. They're an evolutionary dead end. Complex multicellular life can't evolve from those because the conditions are unfavorable chemically for anything more complex. (How do I dare suggest that? Well, there's this 9,000-mile-wide lab that's been operating for over four billion years right outside. Even the truly weirdo stuff at the bottom of the oceans near the geological rifts hasn't gotten very complex--and those conditions are much nicer than the places that the bacteria inhabit.)
When you know the science, you understand the boundaries. When you don't know the science, you don't even understand that the boundaries exist. From that latter perspective, honest and justifiable doubt will look like arrogance.
Alright, you are right, it does occupy a very narrow range. Here. I know what the models, and data, and computations say. But all of it, is based on life as it occurs on this planet. The results are showing a narrow range, because the source comes from a narrow range. Which is why I say it is arrogant to an extent to say that all life that could possibly exsist in this universe would have to occupy that same range that we occupy on this planet. It is healthy to challenge, but to blantantly, and obstinently say that its not right its not possible, it cannot be done with out first verifying the findings is fallacy, and is poor science all together. Rather than sit and argue, and lament, and blame over the findings, why not wait for independant verification, or disproval. Its not the "I have my doubts" its the "I think your wrong because I don't think its possible" Where is the data, the evidence, the proof that your reasoning is sound, and that your logic is correct. Where is the proof that they did not do the experiement right, and that the results are tainted? To do this once is a fluke, to do this twice is potential, and a third time is proof.
And for the record, I do understand what you mean by boundries, but again they are boundries for life as we currently understand it, life that has originated from this world, but keep in mind that the only reason why we are having the conversation in the first place is because a group of scientists dared to believe that life could exsist outside of the boundries established on this planet. To narrow ones point of view to that sole of what is known, and to omit the possibility of what might be, is fallacy. There is no more prevalent example of that than M theory, which brought about the acceptance that alternate realities may possibly exsist, when previously the idea of which was utterly preposterous.
Controversy makes Science. It's the paradox that most times moves knowledge. If it wasn't for the weird orbit of Mars we probably would still be flying in circles. If it wasn't for Mercury, then Einstein theory would have a harder path to show its truthfulness. So, what's really wrong for the someone giving a chance for Arsenic as a part of Life's building blocs? Let me ask you one question - do you really think you may find the secret of Life without a bumpy road ahead? Maybe this Arsenic story is wrong from the very start. Or maybe Arsenic's role is being misinterpreted and someone will find something even more funny and more paradoxical story than what we may be seeing now. Or maybe it is really true and we have to go with it. Or maybe... Maybe... And maybe...
But there is one sure thing. If you don't put question over the table, you ain't going anywhere. You will stay on that place where meteorites can't fall from the sky. Because one Academy of Sciences said so. Well, if you don't get stuck on a flat Earth. Because that's the place you live, if you don't ask no questions at all. And you don't even need the Church for that. You just don't ask no questions and that's all.
Stop fussing around "The Truth" and get into the question itself. That's where Science is. And it may take a few centuries to answer it.
Specially if some only ask to shut up on every bump.
I like the way science, by its nature, questions itself. I like the way theories are challenged, defended, torn down or strengthened through evidence or lack thereof. It is so much more preferable to, say, religious dogma which cannot stand against honest, reasoned inquiry, and which, by ITS nature, dare not question itself.
I true scientist would be happy with an experiment/paper that showed they were wrong or things could have been done better just as much as if their findings are verified. Real science is the pursuit of knowledge and understanding. Your hypothesis being proven wrong tells you just as much as if it is supported by your research.
The conduct of science is broadly analogous to natural selection, in that an important part of the process is destructive: once a researcher or group of researchers proposes a hypothesis, the rest of us attempt to find ways to destroy it, and if this fails and the hypothesis survives, it's provisionally accepted. The great power of science as a communal enterprise is that the individual researcher or group proposing a hypothesis may well be relatively blind to flaws; the rest of us are there to try to find those flaws. This process should be rather merciless and brutal, and it can last for a long, long time (I think of ALH 84001, the "Nemesis" hypothesis, the protracted punctuated equilibrium vs gradualism flap, and so on).
I've been to conferences that were so "bloody" that wounded presenters left immediately after giving their papers.