Final answer:
In this butterfly population, natural selection led to a shift in the behavior of the larvae, with more larvae crawling under leaves to eat over time. This shift is a result of genetic variation and the selective advantage of crawling under leaves to avoid predation by birds.
Step-by-step explanation:
In this butterfly population, the process of natural selection led to a shift in the behavior of the larvae. Initially, most larvae crawled on top of leaves to eat, but a few larvae hatched and crawled under leaves to eat. Over time, this behavior became more common in the population. This shift in behavior is a result of genetic variation and natural selection.
Genetic variation refers to differences in the traits or characteristics of individuals within a population. In this case, some larvae had a genetic variation that allowed them to crawl under leaves to eat, while others did not. The frequency of the allele responsible for this behavior increased over time, as more and more larvae with this allele survived and reproduced.
Natural selection is the process by which certain traits become more or less common in a population based on their impact on survival and reproduction. In this butterfly population, crawling under leaves to eat provided a selective advantage, as the larvae were less likely to be eaten by birds. As a result, the allele for crawling under leaves to eat became more prevalent in the population.