Question

Which type of natural selection s shown by industrial melanism, observed during the industrial revolution in England?Explain.

Answer 1

Industrial melanism is an evolutionary effect prominent in several arthropods, where dark pigmentation (melanism) has evolved in an environment affected by industrial pollution, including sulfur dioxide gas and dark soot deposits. Sulfur dioxide kills lichens, leaving tree bark bare wherein clean areas it is boldly patterned, while soot darkens bark and other surfaces. Darker pigmented individuals have higher fitness in those areas as their camouflage matches the polluted background better; they are thus favored by natural selection. This change, extensively studied by Bernard Kettlewell, is a popular teaching example in Darwinian evolution, providing evidence for natural selection. Kettlewell's results have been challenged by zoologists, creationists and the journalist Judith Hooper, but later researchers have upheld Kettlewell's findings.