a–A white-winged moth and dark-winged moth on a tree trunk in an unpolluted area. b–A white-winged moth and a dark-winged moth on a tree trunk in a polluted area.
Industrial melanism: In England, it was observed before industrialisation that white-winged moth were more than dark-winged moth. But the situation became reversed after industrialisation. In pre-industrialisation, the tree trunk was covered by white lichen and on white background dark-**** moth could be picked up. The situation changed after industrialisation, the tree was covered by industrial smoke and soots and became dark on which white-winged moth could easily be picked up by predators. It was found that industrial melanism supported evolution by natural selection.
