Final answer:
Population genetics is the science focusing on evolutionary forces affecting allele frequencies within a population's gene pool, crucial for understanding microevolution.
Step-by-step explanation:
Population genetics is a branch of biology that involves the study of allele frequencies in populations and how they change over time under the influence of various evolutionary forces such as natural selection, mutation, genetic drift, and migration.
The subject considers a population's gene pool as the sum of all alleles within it and uses principles like the Hardy-Weinberg equilibrium to understand the stability and changes in this pool.
Factors such as genetic drift, the founder effect, and natural selection can lead to significant genetic shifts within a population, defining its evolutionary trajectory.