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As will be remembered, Kettlewell claimed that lichens growing darker or dying is an important part of the natural selection process. But exactly how true was this?
Research in the last quarter of the 20th century revealed that his prediction did not reflect the truth at all. With their observations in 104 separate points in Britain, David Lees and his colleagues revealed that there was no correlation between melanism and tree lichens; which they commented as being surprising.285 This was confirmed by other studies carried out by American biologists in the same period.286 Furthermore, Kettlewell had accepted that there was a drop in melanism in moths, before lichens returned with the elimination of air pollution in the 1970s.287
Had Kettlewell's and evolutionists' claims been true, lichens would resumed their place on trees as air pollution was eradicated, after which light-colored moths would again come to constitute the majority. First, in other words, it was essential for moths to have places to rest on and hide in. However, it was definitively demonstrated that this was not the case. For example, Professor Bruce Grant and his colleagues showed that the ratio of light-colored moths exceeded 93% in a region with a very sparse lichen covering.288 They made an important comment: "We suggest that the role of lichens has been inappropriately emphasized in chronicles about the evolution of melanism in peppered moths."289
Theodore Sargent from Massachusetts University and his team stated that the level of melanic moths had recently dropped in North America, and that this was perplexing in the light of the classical scenario.290
In short, the presence or absence of lichens has no effect on moths. Kettlewell's thinking that lichens were a part of the supposed evolutionary process was a product of another error, as you'll soon see.
References
- D.R. Lees, E.R. Creed, and L.G. Duckett. "Atmospheric pollution and industrial melanism." Heredity 30, 1973. pp. 227-232. ↩
- T.D.Sargent , "Melanism in moths of central Massachusetts (Noctuidae, Geometridae)," Journal of the Lepidopterists' Society, 28: 1974, pp. 145-152. ↩
- Bernard Kettlewell, The Evolution of Melanism, Oxford: Clarendon Press, 1973 ↩
- B.S. Grant, A.D. Cook, C.A. Clarke, and D.F. Owen, "Geographic and temporal variation in the incidence of melanism in peppered moth populations in America and Britain," Journal of Heredity, Vol. 89, 1998, p. 466. ↩
- B.S. Grant, D.F. Owen, and C.A. Clarke, "Parallel rise and fall of melanic peppered moths in America and Britain," Journal of Heredity, Vol. 87, 1996, p. 351. ↩
- T.D. Sargent, C.D. Millar, D.M. Lambert, "The ‘classical' explanation of industrial melanism: assessing the evidence," Evolutionary Biology, Vol. 30, 1998, pp. 316-317. ↩