How did industrial pollution change moth coloration in England and Europe?

During the Industrial Revolution, industrial pollution caused a significant shift in moth coloration in England and Europe, a phenomenon known as industrial melanism.21

Before industrialization, many moth species—such as the peppered moth—rested on tree trunks covered in light-colored lichens, which provided effective camouflage against bird predators. As coal-based air pollution increased, soot blackened the trees and killed the lichens. This environmental change destroyed the protective background for light-colored moths, making them highly visible and vulnerable to predation.231

Conversely, dark-colored (melanic) morphs, which existed as rare mutations, became better camouflaged against the soot-covered bark. Through natural selection, these dark individuals survived at higher rates and passed on their traits, leading to a dramatic increase in the proportion of dark moths across approximately 70 species. Since the 1970s, as air pollution has been curtailed, some populations have shown a reversal in this trend, reflecting the direct impact of environmental quality on biological coloration.231