In the first episode Richard Dawkins explains the basic mechanisms of natural selection, and tells the story of how Charles Darwin developed his theory.
He teaches a year 11 science class about evolution, which many of the students are reluctant to accept. He then takes them to the Jurassic Coast in Dorset to search for fossils, hoping that the students can see some of the evidence for themselves.
Dawkins visits Nairobi, where he interviews a prostitute who seems to have a genetic immunity to HIV, and talks to microbiologist Larry Gelmon. He goes on to predict that genetic immunity to HIV is a trait that will become more prevalent in the community over time.
Part 2: The Fifth Ape
In the second episode Richard Dawkins deals with some of the philosophical and social ramifications of the theory of evolution.
Dawkins starts out in Kenya, speaking with palaeontologist Richard Leakey. He then visits Christ is the Answer Ministries, Kenya's largest Pentecostal church, to interview Bishop Bonifes Adoyo. Adoyo has led the movement to press Kenya's national museum to sideline its collection of hominid bones pointing to man's evolution from ape to human. The collection includes the Turkana Boy discovered by Kamoya Kimeu, a member of a team led by Richard Leakey in 1984.
Dawkins discusses social darwinism and eugenics, explaining how these are not versions of natural selection, and that "Darwin has been wrongly tainted".
He then meets with evolutionary psychologist Steven Pinker to discuss how morals can be compatible with natural selection. He goes on to explaining sexual selection, with peafowls as an example. To find out whether sexual selection plays a role for altruism and kindness among humans, he visits women who are looking for sperm donors, as well as a sperm bank manager. Dawkins also explains kin selection and selfish genes.
Part 3: God Strikes Back
In the third and final episode, Dawkins explains why Darwin's theory is one of history's most controversial ideas.