Industrial melanism of the peppered moth illustrates the phenomenon of

Industrial melanism of the peppered moth illustrates the phenomenon of directional natural selection.

In England, there were more white-winged moths on trees than dark-winged (melanic) moths before industrialisation. After industrialisation, there were more dark-winged moths in the same area, i.e., the proportion was reversed. This is because the dark-winged moths that were able to camouflage themselves survived and left more offspring. In a mixed population, those that can better-adapt, survive and increase in population size.