The Incredible Human Journey is a five-episode, 300-minute, science documentary film presented by Alice Roberts, based on her book by the same name.

She then explains that genetics suggests that all non-Africans may descend from a single, small group of Africans who left the continent tens of thousands of years ago.

In the second episode, Roberts travels to Siberia and visits an isolated community of indigenous people who still practice reindeer hunting.

Roberts then explores an alternative to the Out of Africa theory, the multiregional hypothesis that has gained support in some scientific communities in China.

Roberts visits the Zhoukoudian caves, in which Peking Man, the supposed Homo erectus ancestor of the Chinese, was discovered.

Finally, Roberts interviews Chinese geneticist Jin Li, who ran a study of more than 10,000 individuals scattered throughout China from 160 ethnic groups.

She suggests that the principal difference between them and Homo sapiens was the latter's ability to create art, and visits the cave paintings at Lascaux.

She discusses the theories about why Europeans have white skin and describes the birth of agriculture and the societal changes that took place as a result, visiting the spectacular Neolithic temple at Göbekli Tepe, in southeastern Turkey.

She describes the traditional theory that the first Americans were the Clovis culture, who arrived through an ice-free corridor towards the end of the Ice Age 13,000 years ago.

She concludes by noting that, when Europeans arrived in 1492, they did not recognize Native Americans as fully human, but that modern genetics and archaeology proves that we all ultimately descend from Africans.