Taking the example of Peppered moth, explain the action of natural selection. What do you call the above phenomenon ?

Explanation

(i) Natural selection can be explained clearly through industrial melanism. Industrial melanism is a classical case of Natural selection exhibited by the peppered moth, Biston betularia.
(ii) These were available in two colours, white and black.
(iii) Before industrialization peppered moth both white and black coloured were common in England. Pre-industrialization witnessed white coloured beackground of the wall of the buildings hence the white coloured moths escaped from their predators.
(iv) Post industrialization, the tree trunks became dark due to smoke and soot let out from the industries. The black moths comouflaged on the dark bark of the trees and the white moths were easily identified by their predators.
(v) Hence the dark coloured moth population was selected and their number increased when compared to the white moths.
(vi) Nature offered positive selection pressure to the black coloured moths. The above proof shows that in a population, organisms that can adapt will survive and produce more progenies resulting in increase in population through natural selection.