Assertion: Moths living in the industrial areas became dark to match body colour to the tree trunks.

Question

Assertion: Moths living in the industrial areas became dark to match body colour to the tree trunks.\ Reason : Smoke from industries covered the tree, trunks, making them appear dark and helped dark moths to escape.\

Professor PC Thomas Classes · Answer

(d) : Industrial melanism is the increase of melanic (dark) forms of an animal in the areas of industrial pollution. The most common example is of peppered moth which existed in two strains (forms) : light coloured (white) and melanic (black). In the past, bark of trees were covered by whitish lichens, so white moths escaped unnoticed from predatory birds. After industrialisation lichens disappear due to pollution, so the white moths were selectively picked up by birds. But black moths escaped unnoticed so they managed to survive resulting in more population of black moths and less population of white moths. Thus, industrial melanism supports evolution by natural selection.