The peppered moth population in a locality has light and dark moth varieties. what is the likely cause of a relatively lower population of dark moth variety in the locality? a pollution-free environment increasing lichen growth. b highly polluted environment increasing lichen growth. c pollution-free environment covering the barks with black soot. d highly polluted environment covering the barks with black soot.

Answer: Option A Pollution free environment increasing lichen growth.

Explanation :

The peppered moth has two varieties dark and light.The difference in colour of these two moths is due to industrial melanism which resulted in the evolution of these moths.Earlier, in a pollution free environment the moths were majorly light coloured as they could easily camouflage against the bark of the tree covered with lichen.However, with industrialization the gases like suplhur dioxide killed the lichens covering the tree and hence, the moths evolved to be of darker color to easily camouflage against the now lichen free dark bark.

Thus, in a pollution free environment the lichen growth will increase and thus, the dark moths will find it difficult to camouflage and hence, there population will decrease.