Our greatest living scientist constructs a history of the theory of evolution, linking together the work of six visionaries from Charles Darwin to Svante Pääbo by way of Motoo Kimura, Ursula Goodenough and Richard Dawkins. The outlier in the six is H.G. Wells, the novelist. According to Dyson, Wells was the first person to grasp the significance of “cultural evolution”, a process said here to be at least equal in importance to biological evolution. Cultural evolution consists of “changes in the life of our planet caused by the spread of ideas rather than by the spread of genes”