Second (of five) part of the 2008 Channel-4 documentary 'Life, Darwin & Everything'. The documentary is part of the series 'The Genius of Darwin'. In this episode Richard Dawkins explains the basic mechanisms of natural selection, and tells the story of how Charles Darwin developed his theory. He teaches a young 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.