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From Nature: Peppered again with moth story

Thumbnail for version as of 22:50, 15 June 2006
Olaf Leillinger at 2006-06-14

Here Gwyneth Dickey Zakaib tells us that the gene that codes for colour in the Darwin textbook icon, the peppered moth, has been located (“The peppered moth’s dark genetic past revealed: Researchers find that a single ancestor is responsible for the ‘best example’ of natural selection.”).

The sacred story is recounted in a muted form, which is as much acknowledgement as Nature News (April 14, 2011) could accord to the considerable body of evidence that it is more aptly called the peppered myth:

Thumbnail for version as of 06:27, 20 June 2006
Olaf Leillinger at 2006-06-13

Most textbooks fail to mention, however, that the peppered moth story began to unravel in the 1960s, when biologists noticed that dark moths were unexpectedly plentiful in some unpolluted locations. When anti-pollution legislation led to cleaner air in the 1970s, light-colored moths made a comeback; but, contrary to theory, the comeback occurred without corresponding changes in tree trunks.

Then, in the 1980s, biologists realized that peppered moths almost never rest on tree trunks (as Kettlewell wrongly supposed when he initially released the moths onto tree trunks, creating atypical conditions). Instead, these night-flying insects probably spend their days hiding underneath horizontal branches high up in the trees, where they can’t be seen.

In 1998, University of Chicago evolutionary biologist Jerry Coyne wrote: “From time to time, evolutionists re-examine a classic experimental study and find, to their horror, that it is flawed or downright wrong.” According to Coyne, the fact that peppered moths rarely rest on tree trunks “alone invalidates Kettlewell’s release-and-recapture experiments, as moths were released by placing them directly onto tree trunks.” Coyne concluded that this “prize horse in our stable of examples” of natural selection “is in bad shape, and, while not yet ready for the glue factory, needs serious attention” (Nature, Nov. 5, 1998).

Question: Why do people search for evidence of what they also proclaim is overwhelmingly demonstrated (= Darwinian evolution)? And why do they never seriously wonder why most people don’t believe in their wonder-working icons?


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