By Professor Christopher Stringer FRS, Merit Researcher, Natural History Museum
Human evolution can be divided into two main phases. A pre-human phase in Africa prior to 2 million years ago, where walking upright had evolved but many other characteristics were still essentially ape-like; and a human phase, with an increase in both brain size and behavioural complexity, and an expansion from Africa. Evidence points strongly to Africa as the major centre for the genetic, physical and behavioural origins of humans, but new discoveries are prompting a rethink of some aspects of our evolutionary origins.