Evolutionary biologist Richard Dawkins spends five lectures making the case that natural selection, not design, explains the living world, in a series recorded for the Royal Institution Christmas Lectures for Children. He opens by holding up a totem pole used in ancestor worship to argue that studying ancestry is the key to understanding evolution, then contrasts the human body's abilities with the clumsiness of machines built to copy them. A second lecture uses rocks and crystals to show what unplanned physical law can produce without anyone designing it. In the third, a stick insect and a leaf insect perched on his hand demonstrate camouflage so exact it looks engineered. The fourth lecture turns on a small girl's answer when Dawkins asks what flowers are for: she says they exist for us, which he uses to unpick centuries of thinking, Genesis included, that nature was built around human benefit. Douglas Adams appears as a guest across the run. The lectures rely on live demonstrations and animals rather than narration to make each argument.