The peppered moth evolution demonstrates color change in response to environmental soot. What is the key pattern observed?

The peppered moth evolution demonstrates color change in response to environmental soot. What is the key pattern observed?

• A. White to black to white
• B. Black to white to black
• C. No color change
• D. Random color changes

Answer: (A)

This demonstrates how a trait can shift as environmental conditions change, through natural selection acting on camouflage. In the peppered moth, there are light and dark forms. Before heavy industrial pollution, bark was light due to lichens, so the light-colored moths were better camouflaged and more likely to survive. With industrial soot darkening the trees, the dark form gained the advantage and increased in the population. After pollution declined and the trees returned to a lighter appearance, the light form once again had higher survival, and its numbers rose. So the overall pattern observed is white to black to white as the environment shifts.

This demonstrates how a trait can shift as environmental conditions change, through natural selection acting on camouflage. In the peppered moth, there are light and dark forms. Before heavy industrial pollution, bark was light due to lichens, so the light-colored moths were better camouflaged and more likely to survive. With industrial soot darkening the trees, the dark form gained the advantage and increased in the population. After pollution declined and the trees returned to a lighter appearance, the light form once again had higher survival, and its numbers rose. So the overall pattern observed is white to black to white as the environment shifts.