Hank describes the five factors that explain changes in allele frequency, which are at the heart of how and why evolution happens. The five factors he describes are: natural selection, sexual selection, mutation, genetic drift, and gene flow.
Hank provides background information on the biologist who contributed to evolutionary history: Charles Darwin. He also explains the four principles of Darwin's idea of natural selection, which are variation, heritability, struggle for existence, and survival and reproduction rates.
Key Words: Genetic Drift, Fitness, Variations of Phenotype, Heritable, The Struggle for Existence, Survival and Reproduction Rates