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The evolution of the peppered moth is an evolutionary instance of colour variation in the moth population as a consequence of the Industrial Revolution. The concept refers to an increase in the number of dark-coloured moths due to industrial pollution, and a reciprocal decrease in the population in a clean environment. Hence, the phenomenon is called industrial melanism. It is the first recorded and experimented case of Charles Darwin's natural selection in action, and remains as a classic example in the teaching of evolution. Sewall Wright described it as "the clearest case in which a conspicuous evolutionary process has actually been observed." The dark-coloured or ''melanic'' moths (''carbonaria'' variety) were not known prior to 1811. After field collection in 1848 from Manchester, an industrial city in England, the frequency of the variety was found to have increased drastically. By the end of the 19th century it almost completely outnumbered the original light-coloured type (''typica'' variety). The evolutionary importance of the moth was only speculated upon during Darwin's lifetime. It was only 14 years after Darwin’s death, in 1896, that J.W. Tutt presented it as a case of natural selection. Bernard Kettlewell was the first to investigate the evolutionary mechanism behind peppered moth adaptation, between 1953 and 1956. He found that a light-coloured body was an effective camouflage in a clean environment, such as in Dorset, while the dark colour was beneficial in a polluted environment like in Birmingham. This selective survival was due to birds which easily caught dark moths on clean trees, and white moths on trees darkened with soot. The story, supported by Kettlewell's experiment, became an example of Darwinian evolution used in standard textbooks.〔Miller, Ken (1999). ''(The Peppered Moth: An Update )''〕 However, failure to replicate the experiment and criticism of Kettlewell's methods by Theodore David Sargent in the late 1960s led to general scepticism. When Judith Hooper's ''Of Moths and Men'' was published in 2002, Kettlewell's story was more sternly attacked, accused of fraud, and became widely disregarded. The criticism became a major argument for anti-evolutionists. Michael Majerus was the principal defender. His seven-year experiment beginning in 2001, the most elaborate of its kind in population biology, the results of which were published posthumously in 2012, vindicated Kettlewells' work in great detail. This restored peppered moth evolution as "the most direct evidence", and "one of the clearest and most easily understood examples of Darwinian evolution in action". == Origin and evolution == Before the Industrial Revolution, the black peppered moth was rare. The first black specimen (of unknown origin) was kept in the University of Oxford in 1811. The first live specimen was caught by R.S. Edleston in Manchester, England in 1848, but he reported this only 16 years later in 1864 in the journal ''Entomologist''. Edleston notes that by 1864 it was the more common type of moth in his garden in Manchester. The light-bodied moths were able to blend in with the light-coloured lichens and tree bark, and the less common black moth was more likely to be eaten by birds. As a result of the common light-coloured lichens and English trees, therefore, the light-coloured moths were much more effective at hiding from predators, and the frequency of the dark allele was about 0.01%. During the early decades of the Industrial Revolution in England, the countryside between London and Manchester became blanketed with soot from the new coal-burning factories. Many of the light-bodied lichens died from sulphur dioxide emissions, and the trees became darkened. This led to an increase in bird predation for light-coloured moths, as they no longer blended in as well in their polluted ecosystem: indeed, their bodies now dramatically contrasted with the colour of the bark. Dark-coloured moths, on the other hand, were camouflaged very well by the blackened trees.〔 The population of dark-coloured moth rapidly increased. By the mid-19th century, the number of dark-coloured moths had risen noticeably, and by 1895, the percentage of dark-coloured moths in Manchester was reported at 98%, a dramatic change (of almost 100%) from the original frequency.〔 This effect of industrialization in body colour led to the coining of the term "industrial melanism".〔 The implications of industrial melanism to Charles Darwin's natural selection was evident during his lifetime. Albert Brydges Farn (1841–1921), a British entomologist, wrote to Darwin on 18 November 1878 to discuss his observation of colour variations in the Annulet moth (then ''Gnophos obscurata'', now ''Charissa obscurata''). He noted the existence of dark moths in peat in the New Forest, brown moths on clay and red soil in Herefordshire, and white moths on chalk cliffs in Lewes. He suggested this variation as an example of "survival of the fittest". Surprisingly, scientific explanation came only in 1896, 14 years after Darwin’s death, when J.W. Tutt explicitly linked peppered moth melanism to natural selection. However, in a letter to Darwin, Farn explained his discovery of industrial melanism in Gnophos obscurata. This letter shows that Darwin could have confirmed his theory of natural selection, had he realized the potential significance of the information that Farn provided. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Peppered moth evolution」の詳細全文を読む スポンサード リンク
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