Answer:
Reproduction, heredity, variation in physical characteristics and variation in number of offspring per individual.
Explanation:
The heredity in the speckled forms of the moths were the most common form as they camouflaged much easier, while the black moths would be eaten off by predators as they could not camouflage as well. With the industrial revolution the coal and other things made many trees in the forest black, because of the physical variation the black moths now blended in while the speckle moths couldn't and the roles were reversed.
