Final answer:
The population of black moths has changed over time due to the level of industrial pollution. With the Industrial Revolution, the dark-colored moths became more prevalent due to better camouflage. However, as factories became cleaner and soot emissions decreased, the lighter-colored moths have made a comeback.
Step-by-step explanation:
Historically, the population of black moths, also known as peppered moths, has fluctuated in response to changes in the environment, specifically relating to the amount of industrial pollution. During the Industrial Revolution, there was a notable increase in the number of dark-colored moths due to their enhanced camouflage against soot-covered trees. This phenomenon is referred to as industrial melanism. Predators were more likely to see and eat lighter-colored moths, which led to the predominance of the darker variety.
With recent efforts to make factories cleaner and reduce soot emissions, there has been a subsequent impact on the distribution of moth color within the population. Light-colored moths are now experiencing a resurgence as the environment returns to a cleaner state, with tree bark regaining its lighter color. Therefore, the light form of the peppered moth is now better camouflaged against predators, leading to an increase in their numbers compared to the once-favored dark form.