Which real-world example illustrates natural selection in response to environmental change?

• A. A population's trait frequencies remain unchanged despite environmental change.
• B. Bees growing longer wings in a single generation due to wind.
• C. Dogs learning tricks that improve training ability.
• D. Peppered moth color change in response to industrial soot

Answer: (D)

Natural selection in response to environmental change happens when there is heritable variation in a trait, the environment alters which variants survive and reproduce, and over generations the advantageous trait becomes more common in the population. The peppered moth example shows this clearly: in clean environments with lichen on trees, light-colored moths were better camouflaged and less likely to be eaten, while darker moths were more visible and had lower survival. When industrial soot darkened tree bark, the darker form gained a survival advantage and left more offspring, so the frequency of dark-colored moths rose in polluted areas. Over time, the population shifted toward the color variant that matched the changed environment, illustrating natural selection driven by environmental change. If a scenario shows no change in trait frequencies despite environmental shifts, a single-generation change that doesn’t reflect inherited variation, or learning that isn’t passed on genetically, it doesn’t demonstrate natural selection in response to the environment.