The change in gene frequency over a period of time is called:

• A. Mutation
• B. Evolution
• C. Adaptation
• D. Migration

Answer: (B)

Evolution describes how allele frequencies in a population change from generation to generation. This shift in genetic makeup occurs through mechanisms like natural selection, genetic drift, gene flow (migration), and mutation introducing new variants. Saying evolution captures the overall process of changing gene frequencies over time, whereas mutation is just a source of new alleles, gene flow is one mechanism that can cause such changes, and adaptation refers to populations becoming better suited to their environment as a result of evolution. So the term that best fits the idea of change in gene frequency over time is evolution.