Question

The peppered white moth Biston betularia is very common in England. This moth rests on branches of trees and is able to blend with the background. The darker melanic form appeared much later and is plentiful in industrial regions. The original white form is absent in polluted regions because:

• A. The mutant form has eliminated them
• B. The original form is easily visible and predated upon by birds
• C. The smoke and soot from factory chimneys has killed them
• D. The heathier, cleaner atmosphere in the non polluted regions is more suitable for the peppered moth

Answer 1

The correct option is B The original form is easily visible and predated upon by birds

Like many moths in forests, the peppered moth tends to rest (or "perch") on tree trunks during the day. They do most of their flying at night. So it would probably be a good thing if the moths look similar to the trees that they perch on, right? Then they can be camouflaged from birds that want to eat them. Before the Industrial Revolution, the light peppered moth was common, while the dark form was very rare. The light moths blended in with the light-colored trees. However, the Industrial Revolution changed the tree colors. As the trees darkened with soot, the light-colored moths were easier to see. They were eaten by birds more and more, while the rare dark-colored moths blended in better on the darker trees. This made the dark-colored moths have a higher survival rate. They lived longer and passed their dark-colored genes onto their offspring or young.

So, the correct answer is 'The original form is easily visible and predated upon by birds'.