Question

White moths were found in huge numbers in the city of birmingham. These could be easily camouflaged by the trees. Because of sudden industrail development, the trees in the city were covered with soot. How many will this change affect the population of white moths

Answer 1

Because of sudden industrial development, if the trees will be covered with soot then in that case the population of white moths will be reduced drastically. The reason why their population will be reduced is that because of the soot the trees will become black in color and the white moths will be easily visible on the black background and predators will be easily able to see them because of contrasting colors. This kind of selection is known as directional selection in which one extreme trait is selected.