Question

prior to the industrial revolution, the peppered moth was almost entirely light - colored with dark spots. however, during the industrial revolution, factories spewed large amounts of soot and ash into the air, covering the barks of trees on which the peppered moths liked to sit. over time, the population of peppered moths became mostly a dark color.
which statement best describes why there was a shift in the color of the peppered moths?

directional selection occurred. peppered moths with light - colored wings slowly developed dark - colored wings, leading to the shift in wing color of the population

directional selection occurred. peppered moths with dark - colored wings had increased fitness because they were better camouflaged against the now darker bark of the trees

stabilizing selection occurred. peppered moth wings with dark - colored wings had increased fitness, leading to the shift in the wing color of the population.

stabilizing selection occurred. peppered moths mated with each other, creating hybrid wing colors that provided better protection from predators.

Explanation:

1. Analyze the first option: Moths don't "develop" new colors individually in this way; evolution acts on populations via selection, not individual development of new traits. So this is incorrect.
2. Analyze the second option: Directional selection is when one extreme phenotype is favored. After trees darkened, dark - colored moths were better camouflaged (had higher fitness, as they were less likely to be preyed upon), so the population shifted towards dark color. This matches the peppered moth scenario.
3. Analyze the third option: Stabilizing selection favors intermediate phenotypes, but here the population shifted to a different extreme (dark color), so it's not stabilizing selection.
4. Analyze the fourth option: There's no indication of hybrid wing colors being created for protection, and the selection type is misidentified (not stabilizing), so this is incorrect.

Answer:

Directional selection occurred. Peppered moths with dark - colored wings had increased fitness because they were better camouflaged against the now darker bark of the trees