In the Guardian’s weekly podcast today, I discuss the Wolfe-Simon Mono Lake bacteria paper with science editor Alok Jha and astrobiologist Zita Martins. Our post-mortem covers the hype before and after the press conference; the questions raised about the study’s methods and findings; NASA’s attempt to ignore (and get everyone else to ignore) those questions; some broader issues of how science should be evaluated; and, briefly, the difference between doing science to prove a point and doing science to test a question.
You can listen to the podcast over yonder. Meantime, I wanted to note here something that struck me repeatedly in the last week, and which came up obliquely a couple times in the podcast: A sense of history can serve one well during a fracas like this. One feels repetitive warning that those who don’t know history are doomed to repeat it — but by golly, it keeps happening!
So what can zooming back a bit teach or remind us about?
First, we should remember that the printed science journal was originally created to expand the discussion of science, allowing it to move beyond face-to-face contact at salons and saloons and meetings and into a medium more widely shared. It’s silly to now cite the printed journal’s traditions as a way to limit discussion.
Second, contrary to statements otherwise, it’s good for the public to see this mess. Scientists have long debated methods and findings in outside peer-review journals and closed conferences. In the 18th and 19th centuries in particular, they argued vigorously in popular magazines, lectures, and public debates.
This is perfectly natural and perfectly healthy. In fact, it could actually help ease the rampant politicization of science rather than aggravate it. This Lake Mono bug, for instance, is a controversial scientifically but not politically. So it’s good that people see the scientific debate here is messy and spirited and confusing and even sometimes a bit nasty. Because if the general public sees this sort of row in routine findings — if they understand that science routinely sparks arguments over data and method — they’re less likely to see such messy debate as sinister when they see it in something like climate science.
Both failure and success offer great opportunities. I’ve been thinking about this a lot. Some 150 years ago, another bold-thinking biologist, Thomas Huxley, aka Darwin’s bulldog, suffered a reversal after he claimed to have discovered a “primoridal ooze” that he dubbed BathybIus. This episode was increasingly on my mind as the problems with the arsenic paper came increasingly to light.
The Bathybius discovery occurred during the long debate over Darwin’s theory or evolution in the mid-1800s. Huxley liked Bathybius — perhaps he saw Bathybius — partly because it seemed the sort of primordial life form from which all other life might arise, which in turn supported Darwin’s idea of constantly evolving life forms. I tell a brief version of this story in my book Reef Madness: Charles Darwin, Alexander Agassiz, and the Meaning of Coral:
Darwin’s just-published theory of evolution … held that evolution proceeded rapidly in fast-changing environments and slowly amid stasis. If this were true, the presumably little-changing [ocean] deep might include unchanged species — “living fossils” — from the evolutionary past. This notion was encouraged when … Thomas Huxley (an able working biologist when not writing or debating) … found in some specimen bottles from [one of his] early deep-sea expeditions a mysterious, protoplasmic goo — a “primordial ooze” or “living slime” — that he proposed might be both the base of the ocean food chain and the bottom rung of the evolutionary ladder. He called it Bathybius haecklii after his Darwinist compatriot Ernst Haeckel.
And he publicized it heavily — trumpeted it in Nature, talked it up, wrote about it often, as did others. But 7 years after Huxley discovered it, Bathybius met an ugly death when a scientist on the famous oceanographic expedition taken by the HMS Challenger found that Huxley — well, I’ll let me tell it:
One day, when one of the Challenger scientists poured a large quantity of alcohol into a bottle containing deep-sea ooze and the mixture almost instantly produced something remarkably like the mysterious Bathybius, they realized that Huxley’s ancient slime was simply a new goo produced by the reaction between ordinary ooze made up of planktonic skeletons and alcohol. The stuff in Huxley’s tubes had apparently been formed more slowly by the traces of alcohol left after washing. [Chief scientist] Thomson immediately wrote Huxley, breaking the news with remarkable tact, and Huxley promptly sent the letter to be published in Nature along with a graceful and funny letter confessing his error.
Wolfe-Simon and company may well prove out their arsenic theory and show us that GFAJ really does live on arsenic and incorporates the stuff into its DNA. If so, they’ll astonish even more people than they already have. And if they go on to find the sort of shadow biosphere that they talk about, we’ll be truly wowed — and they’ll have rights to be every bit as triumphant as Huxley was contrite.
At this point, however, there remains a frightening (and unnecessary) possibility that the team has spoken a bit too soon. They not only apparently did the equivalent of failing to wash their glassware thoroughly enough, but failed to do a fairly simple mass spectrometry analysis that several scientists say would decisively show whether the bacteria took arsenic into its DNA — their biggest and most consequential claim. Several scientists wondered why they didn’t do this simple test. If it’s as decisive a test as these critics say, the authors’ failure to run it — and Science’s failure to ask for it — is mystifying. As one scientist told Zimmer, “The curious thing is that if getting powerful data is so easy, why was this printed in its current form?”
It was also this failure that led another critic levy perhaps the most damning criticism, which was that “the paper represents something that all graduate students are told to think about – develop experiments that are aimed to reject your hypothesis, not support it. If you cannot reject it, then you must accept it. These experiments [in the Wolfe-Simon paper] in most cases were shown to ’support’, not test the central hypothesis. It’s a newbie mistake and the mentors, reviewers and editors are as much at fault for not catching that as anyone.”
Everyone makes mistakes. Huxley didn’t wash his bottles well enough, and so created a mess he thought was a new life form. If they’re proven wrong, Wolfe-Simon and colleagues can take solace in some good company who’ve also seen what they wanted to see — a common error that scientists call confirmation bias. Huxley did it, and as I explain in my book, Darwin did too, when he made an early but painful mistake about the geology of Glen Roy. That youthful mistake — he downplayed some evidence contrary to his theory and magnified some that supported it — led to a humiliating reversal at the hands of Louis Agassiz. And Louis would later suffer a much greater reversal, partly because of how Darwin responded to his mistake.
The key thing is that when confronted with contrary evidence, both Huxley and Darwin admitted their mistakes and learned from them. Darwin’s insights from his bumble at Glen Roy helped him forge the brilliant balance of imagination and rigor that were his mark.
If mass spectrometry and other suggested tests are indeed definitive tests of Wolfe-Simon’s arsenic claims, she and her co-authors will likely soon be proven (or, if they’re really on the ball, prove themselves) either profoundly mistaken or stunningly correct. Either way, they’ll face an important moment. Both grave failure and spectacular success bring their opportunities for growth. Here too history offers models:
Darwin learned both boldness and caution from his [mistake at Glen Roy]. Louis Agassiz, however, took from Glen Roy an opposite lesson: He felt emboldened to push his speculative theories ever further. At Glen Roy, Darwin had stumbled, collected himself, and adjusted his gait. Louis had sprung across a valley and landed safely. He would soon put so much faith in his leaps that even when his support was delusory, he would land and feel solid ground.
This lack of humility did not serve him well.
Image: The murky valley that is Glen Roy. Courtesy Wikipedia Commons.