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Why did melanic moth populations decline after air pollution was reduced in England?

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How does an anole change its color? — coloration The anole changes color in response to its stress level.

The decline of melanic moth populations in England following the reduction of air pollution is a direct result of shifting natural selection pressures.1

During the Industrial Revolution, coal soot killed lichens and darkened tree trunks, which provided a camouflage advantage to dark-colored (melanic) moths while making light-colored moths highly visible to bird predators. As pollution control efforts improved air quality, the lichens began to recover and tree trunks returned to their lighter, natural appearance.231

Consequently, the dark coloration that once provided concealment became a disadvantage, rendering melanic moths more conspicuous to predators than the light-colored morphs. This reversal in environmental conditions caused the selective advantage to shift back toward the light-colored moths, leading to a decline in the proportion of melanic individuals within these populations.21