It’s a familiar story. A striking, though minor, scientific finding, is used to illustrate a well-established scientific theory, and becomes the target of those opposed to the theory, and to science in general, for political or religious reasons. Minor errors in and procedural criticisms of the work supporting the finding are conflated into accusations of fraudulent conspiracy that are then used to attack the theory as a whole. Distorted versions of the whole story circulate around the parallel universe of antiscientific thinktanks, blogs and commentators, rapidly being taken as established fact.
This time, the story looks set to have a happy ending. The case of industrial melanism in the peppered moth was long used as a textbook example of evolution (I remember it from high school). Before the Industrial Revolution, the peppered moth was mostly found in a light gray form with little black speckled spots. The light-bodied moths were able to blend in with the light-colored lichens and tree bark, and the less common black moth was more likely to be eaten by birds. As industrial pollution increased, blackening trees, black forms became more prevalent. With more recent declines in pollution, the process is set to be reversed.
But in the late 90s, it turned out that some of the experimental work used to establish the bird predation hypothesis had been unacceptably sloppy, at least by modern standards. Under ferocious attack from creationists, some textbooks stopped mentioning the peppered moth. Claims of fraud proliferated, and the creationists celebrated a famous victory.
Now for the happy ending (which I found via New Scientist (unfortunately paywalled).
Over the last seven years, Michael Majerus has painstakingly rerun the experiments on bird predation of peppered moths, producing results which he describes as a complete vindication of the peppered moth story, and saying “If the rise and fall of the peppered moth is one of the most visually impacting and easily understood examples of Darwinian evolution in action, it should be taught. It provides after all the proof of evolution.”
Of course, this won’t stop the creationists or their tame journalists and politicians. But as the New Scientist says, this kind of episode shows science at its best, and its enemies at their worst.
Update While I’m at it, a nice piece on skepticism and scientific consensus.