Answer: These types of changes/adaptations occur in order for the peppered moths to camouflage which gives them a higher chance of surviving and producing offspring.
Explanation: When the environment changed, due to pollution, the color of the moth population shifted because light-colored moths became easier to see so they were eaten more often. The darker moths were better camouflaged and more likely to survive and produce offspring. Organisms that survive have a better chance of reproducing so the population continues to grow.