Note: This is the second of two articles in which I discuss the NASA “arsenic bacterium” debacle. The previous one is Arsenic and Odd Lace.
“Those whom the gods wish to destroy they first make mad.” – Anonymous ancient proverb
In the 1961 film The Guns of Navarone, Greek resistance fighters and Allied demolition experts set out to destroy a nest of large cannons so that a rescue convoy can go through the straits the guns overlook. A young Greek who’s part of the mission goes after a group of Germans gunslinger-style, jeopardizing the venture. The Germans cut him to ribbons. When the mission members meet at their rendezvous point, his sister María (Iríni Pappás) says to his partner Andréas (Anthony Quinn, obligatory at that time whenever swarthy ethnics were required): “Tell me what happened.” Andréas replies: “He forgot why we came.”
Last week, NASA administrators forgot why we came. They forgot the agency’s mission, they forgot science, they forgot their responsibility to their own people and to the public. Instead, they apparently decided that all publicity is good, as long as they don’t misspell your name.
Ever since I became fully conscious, I’ve dreamed of humanity exploring the stars. These dreams were part of the reason I left my culture, my country, my family and came over here, determined to do research. Every launch made my heart leap. I wept when I saw the images sent by the Voyagers, Sojourner negotiating Martian rocks. I kept thinking that perhaps in my lifetime we might find an unambiguous independent life sample. Then, at long last, astrobiology would lift off and whole new scientific domains would unfurl and soar with it.
Instead of that, last week we got bacterial isolate GFAJ-1. We got an agency which appears so desperate that it shoved experiments with inadequate controls into a high profile journal and then shouted from the rooftops that its researchers had discovered a new form of life (de facto false, even if the results of the increasingly beleaguered Science paper stand).
This is not the first or only time NASA administrators have been callously cavalier. Yet even though the latest debacle didn’t claim lives like the Challenger incident did, it was just as damaging in every other way. And whereas the Challenger disaster was partly instigated by pressure from the White House (Reagan needed an exclamation point for his State of the Union address), this time the hole in NASA’s credibility is entirely self-inflicted. Something went wrong in the process, and all the gatekeeping functions failed disastrously.
Let’s investigate a major claim in the Science paper: that GFAJ-1 bacteria incorporate arsenic in their DNA, making them novel, unique, a paradigm shift. Others have discussed the instability of the arsenate intermediates and of any resulting backbone. Three more points are crucial:
1. This uniqueness (not yet proved) has come about by non-stop selection pressure in the laboratory, not by intrinsic biochemistry: the parent bacterium in its normal environment uses garden-variety pathways and reverts to them as soon as the pressure is lifted. This makes the “novel life” claim patently incorrect and the isolate no more exotic than the various metallophores and metallovores that many groups in that domain (Penny Boston, Ken Nealson) have been studying for decades.
2. The arsenic-for-phosphorus substitution in the DNA is circumstantial at best. The paper contained no sequencing, no autoradiography, no cesium chloride density gradients. These are low-tech routine methods that nevertheless would give far more direct support to the authors’ claims. Density gradients are what Meselson and Stahl used in 1958 to demonstrate that DNA replication was semi-conservative. Instead, Wolfe-Simon et al. used highly complex techniques that gave inconclusive answers.
The reagents for the methods I just listed would cost less than $1,000 (total, not each). A round of sequencing costs $10 – the price of a Starbucks latte. In a subsequent interview, Oremland (the paper’s senior author) said that they did not have enough money to do more experiments. This is like saying that you hired the Good Year blimp to take you downtown but didn’t have enough money for a taxi back home.
3. Even if some of the bacteria incorporate arsenic in their DNA, it means nothing if they cannot propagate. Essentially, they can linger as poison-filled zombies that will nonetheless register as “alive” through such tests as culture turbidity and even sluggish metabolism.
NASA spokespeople, as well as Wolfe-Simon and Oremland, have stated that the only legitimate and acceptable critiques are those that will appear in peer-reviewed venues – and that others are welcome to do experiments to confirm or disprove their findings.
The former statement is remarkably arrogant and hypocritical, given the NASA publicity hyperdrive around the paper: embargoes, synchronized watches, melodramatic hints of “new life”, of a discovery with “major impact on astrobiology and the search for extraterrestrial life”. This is called leading with your chin. And if you live by PR, you cannot act shocked and dismayed when you die by PR.
As for duplicating the group’s experiments, the burden of proof lies with the original researchers. This burden increases if their claims are extraordinary. The team that published the paper was being paid to do the work by a grant (or, possibly, by earmarked NASA money, which implies much less competition). For anyone else to confirm or disprove their findings, they will have to carve effort, time and money out of already committed funds — or apply for a grant specifically geared to this, and wait for at least a year (usually more) for the money to be awarded. It’s essentially having to clean up someone else’s mess on your own time and dime.
Peer review is like democracy: it’s the worst method, except for all others. It cannot avoid agendas, vendettas, pet theories or hierarchies. But at least it does attempt judgment by one’s peers. Given the kernel of this paper, its reviewers should have been gathered from several disciplines. I count at least four: a microbiologist with expertise in extremophiles, a molecular biologist specializing in nucleic acids, a biochemist studying protein and/or lipid metabolism and a biophysicist versed in crystallography and spectrometry.
Some journals have started to name reviewers; Science does not, and “astrobiology” is a murky domain. If the scientific community discovers that the reviewers for the GFAJ-1 paper were physicists who write sciency SF and had put on the astrobio hat for amusement and/or convenience, Lake Mono will look mild and hospitable compared to the climate that such news will create.
Because of the way scientific publishing works, a lot of shaky papers appear that never get corrected or retracted. As a dodge, authors routinely state that “more needs to be done to definitively prove X.” Even if later findings of other labs completely contradict their conclusions, they can argue that the experiments were correct, if not their interpretation. Colleagues within each narrow domain know these papers and/or labs – and quietly discount them. But if such results get media attention (which NASA courted for this paper), the damage is irreversible.
People will argue that science is self-correcting. This is true in the long run – and as long as science is given money to conduct research. However, the publication of that paper in Science was a very public slap in the face of scientists who take time and effort to test their theories. NASA’s contempt for the scientific process (and for basic intelligence) during this jaw-dropping spectacle was palpable. It blatantly endorsed perceived “sexiness” and fast returns at the expense of careful experimentation. This is the equivalent of rewarding the mindset and habits of hedge fund managers who walk away with other people’s lifelong savings.
By disbursing hype, NASA administrators handed ready-made ammunition to the already strong and growing anti-intellectual, anti-scientific groups in US society: to creationists and proponents of (un)intelligent design; to climate change denialists and young-earth biblical fundamentalists; to politicians who have been slashing everything “non-essential” (except, of course, war spending and capital gains income). It jeopardized the still-struggling discipline of astrobiology. And it jeopardized the future of a young scientist who is at least enthusiastic about her research even if her critical thinking needs a booster shot – or a more rigorous mentor.
Perhaps NASA’s administrators were under pressure to deliver something, anything to stave off further decrease of already tight funds. I understand their position – and even more, that of their scientists. NIH and NSF are in the same tightening vise, and the US has lost several generations of working scientists in the last two decades. Everyone is looking for brass rings because it’s Winner Take All – and “all” is pennies. We have become beggars scrambling for coins tossed out of rich people’s carriages, buskers and dancing bears, lobsters in a slowly heating pot.
NASA should not have to resort to circus acts as the price for doing science. It’s in such circumstances that violence is done to process, to rigor, to integrity. We are human. We have mortgages and doctors’ bills and children to send to college, yes. But we are scientists, first and foremost. We are – must be – more than court jesters or technicians for the powerful. If we don’t hold the line, no one else will.
The paper: Wolfe-Simon F, Blum JS, Kulp TR, Gordon GW, Hoeft SE, Pett-Ridge J, Stolz JF, Webb SM, Weber PK, Davies PCW, Anbar AD, Oremland RS (2010) A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus. DOI: 10.1126/science.1197258.