Question

according to kettlewell, why did the number of dark colored moths increase in industrialized areas?
the lighter colored moths moved out of the area so the dark moths had less competition for food.
the darker moths blended in with the dark colored bark of the tree and were able to avoid predation by birds.
the darker moths had a bad taste so the birds did not eat them.
the darker moths were able to eat the leaves on trees that were covered in soot.

Explanation:

Kettlewell's work focused on industrial melanism. In industrialized areas, pollution darkened tree bark. Dark - colored moths could camouflage better (blend in) with the dark bark. This camouflage helped them avoid being seen and eaten by birds (predation). Lighter - colored moths were more visible and thus more likely to be preyed upon. There is no evidence in Kettlewell's work to support the other options. The first option about competition for food is not the main reason. The third option about bad taste is not relevant to his findings. The fourth option about eating soot - covered leaves is not the key factor in the increase of dark - colored moths.

Answer:

The darker moths blended in with the dark colored bark of the tree and were able to avoid predation by birds.