In the population of Pepper moth, two variants were already existing in the population, the black and the grey. In the absence of industrialisation the grey moths were prevalent because they blended very well with the lichen and moss covered trees camouflage and the predators cannot spot them. The black ones were easily spotted and killed by predators and therefore were fewer in numbers. With industrialisation the stems got covered with black soot. This provided better camouflage to the black variant and their number increased. If the industries had been removed the population of black moths would have declined because as stated earlier they would have been spotted better by predators and therefore be eaten more frequently.