Biology for IGCSE & O level - Variation And Selection (Section 5 - No. 41)
A certain population of moths lives in a forest. Originally, the majority of the moths are light-colored, but over time, the proportion of dark-colored moths increases. Which of the following is most likely responsible for this shift?
Increased air pollution, leading to darker tree bark and better camouflage for dark moths.
A sudden increase in the number of light-colored moths.
A decrease in predation pressure on the light-colored moths.
A new mutation that makes the moths darker.
Explanation
The most likely explanation is natural selection. If the environment changes (e.g., pollution darkening tree bark), the dark moths become better camouflaged, increasing their survival rate and leading to their increased proportion in the population.
Comments (0)
