Question

Industrial melanism in England after 1850 is an excellent example of Natural selection. Explain how?

Answer 1

Industrial melanism is a phenomenon that occurs in soot-covered industrial environments where organisms develop to become more melanistic in order to blend in with the surroundings. This protects them from predators.

Around the period of the Industrial Revolution, the first cases of industrial melanism were reported in the UK. The peppered moth species, which is bright grey, was more prevalent before the Industrial Revolution. By blending in with their surroundings, they were able to avoid being eaten by birds and other natural predators. Dark-coloured or melanistic moths, on the other hand, were uncommon.

But throughout the revolution, air pollution brought on by soot from coal-powered enterprises clouded the surroundings. Due to their inability to blend in with a dark background, these light-coloured moths were chased more frequently by their predators. Their population fell as a result, particularly in the industrial zones. Natural selection is a form of evolution where individuals who are more suited to their environment are chosen to live and generate offspring. Hence, industrial melanism is an example of directional selection where because of environmental changes, a single phenotype is preferred. It causes the allele frequency to move continuously in a particular direction.