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

Mr. Burns makes a political campaign to rally the support of his peers. While doing so, he introduces his three-eyed fish, Blinky, then summons an actor portraying Charles Darwin to explain the concept of evolution.

Charles Darwin struggles with the meaning of his research, and Thomas Huxley tells him that his theory of evolution has "killed God" because it offers a scientific explanation for the species of the world. Darwin realizes that his research will be used as ammunition in favor of science over religion.

Beakman explains that giraffes have long necks so they can eat leaves out of trees. He mentions that heredity has caused them to all have long necks. He then pretends to be Charles Darwin, who explains how natural selection caused the long necks in giraffes.

Sophie discusses fear and explains its purpose: to keep us alive. She illustrates what happens to our bodies when we're scared and mentions the different ways in which fear can be evoked. She then talks about the flight or flight response and references Charles Darwin's "Flinch" experiment that he conducted on himself.