Write a note on Industrial Melanism

Write a note on Industrial Melanism. 

OR

Explain the action of natural selection concerning industrial melanism.

Answer :

• Industrial melanism is the best example of useful variation and Natural selection.
• Industrial melanism was studied by Kettlewell (1845)
• The evolution of darker forms in response to industrial pollution is known as industrial melanism.
• In the industrial area of Britain (England), the soot released from numerous industries is deposited on the tree trunks which made them dark.
• The normal Peppered moth Biston betularia, has a grey (Light) body that matches with the color of lichens on the bark of the tree. Some moths developed melanin. When such dark moths settled on the dark tree trunks, they were not noticed by the predators.
• But the original light-colored moths could be easily noticed and killed by their predators and thus diminished in number gradually.
• The darker variety of moths Biston Carbonaria was at an advantage, they escaped from predators and survived and reproduced resulting in more population of black or dark moths and less population of white moths.
• Dark moths with suitable variation show the ability to face changing environments. Hence industrial melanism is the best example of variations.