A biologist creates a large population of genetically identical individuals by chopping up a light-colored adult sponge into tiny pieces and scattering the pieces randomly across a coral reef. Many of the pieces that land on darker backgrounds are eaten immediately by fish. Some pieces grow into adult sponges, especially pieces that land on light backgrounds. Which statement describes how phenotypic frequency would change over time in this sponge population?

Natural selection

Explanation:

Natural selection is the main mechanism by which populations adapt and change over time to survive in their environment. Individuals in a population exhibit different gene variants or 'alleles' (i.e., individuals exhibit genetic variation). Some of these alleles are associated with phenotypic traits better suited to the environment than others. Natural selection can change allele frequencies in the population, increasing the frequency of the alleles associated with higher fitness, i.e., those alleles associated with lower mortality and the most offspring in a particular environment. Over time, these advantageous alleles become more common in the population. In consequence, natural selection can be considered as a statement on the expected value of allele frequencies under resampling from one generation to the next.