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In addition to the fundamental false assumption that prompted Kettlewell to release moths onto nearby tree trunks, where they don't normally rest, Hooper lists various other problems with his experiments; for example, (1) Kettlewell's moth densities were too high, "in effect, creating a feeding tray," with the intensity of predation recorded in his experiments simply being "a learned response by the local birds"; (2) Kettlewell measured camouflage by his own eye, even though bird vision is quite different from human vision; (3) he and Ford disregarded evidence that selection might operate on caterpillars (through differential mortality when exposed to pollution) instead of on adult moths; and (4) the two men ignored the fact that the main predators of peppered moths are night-flying bats.
Despite problems with the classic story, critics have been notably scarce. One of the few has been University of Massachusetts biology professor Ted Sargent, now retired—the third major protagonist in Hooper's book, and the real hero of the story. A lepidopterist, Sargent has been critical for decades of the camouflage-predation explanation for industrial melanism in peppered moths. In 1998 he and two colleagues wrote in Evolutionary Biology that "there is little persuasive evidence, in the form of rigorous and replicated observations and experiments, to support this explanation at the present time."
For his efforts, Sargent has been "marginalized" and even "demonized" by what Hooper calls "the industrial melanism establishment." (His principal protection, it seems, was that he resisted the modern trend among scientists to get research grants, so he remained free of the political entanglements that muzzled so many of his contemporaries.)
Why was Sargent treated so badly? One reason may simply be the tendency of scientists to cling to theories that are mainstays of their careers. I suspect, though, that something more is involved: a desire to protect the classic story as an icon of Darwinian evolution in action. Although Jerry Coyne is an outspoken evolutionist, and Ted Sargent is no creationist, the evolution-creation controversy fosters a climate in which many Darwinists regard criticism of supposed evidence for evolution as giving aid and comfort to the Enemy.
Ironically, though, the truth or falsity of the peppered moth story is largely irrelevant to the evolution-creation controversy. If the story were true, it would show only a reversible shift in the proportions of two varieties in a preexisting species—a result that even the most uncompromising creationist could accept. And its falsity poses no threat to the most uncompromising evolutionist, because there are now other, better examples of natural selection within existing species.
Nevertheless, many defenders of Darwinian evolution rush to protect the peppered moth icon as though their religion depended on it. In 2000, I wrote a book pointing out that the peppered moth story—though of limited significance in itself—is part of a larger pattern of systematic misrepresentation serving to prop up Darwin's theory. Kevin Padian, a Berkeley professor and president of the National Center for Science Education, a militantly pro-Darwin advocacy group, responded by likening me to the sociopathic antihero of the film The Talented Mr. Ripley. According to Padian, "a particularly egregious example of Mr. Wells's talents is his treatment of the peppered moth." Padian then went on to defend the classic story by claiming that peppered moths "rest on tree trunks 26% of the time" (The Quarterly Review of Biology, March 2002).
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