In the third and final episode, Dawkins explains why Darwin's theory is one of history's most controversial ideas. Dawkins uses this episode to discuss the opposition that evolution has experienced since it was first discovered. He starts by approaching various anti-evolutionists, ranging from John Mackay from Creation Research, Wendy Wright, President of Concerned Women for America, to English school teacher Nick Cowen. In order to address concerns they bring up, he shows the evidence for evolution, including fossil and DNA evidence.