The Director of the British Museum, Neil MacGregor, retells the history of human development from the first stone axe to the credit card, using 100 selected objects from the Museum. Neil goes back two million years to the Rift Valley in Tanzania, where a simple chipped stone marks the emergence of modern humans. One of the characteristics that mark humans out from other animals is their desire for, and dependency on, the things they fashion with their own hands. Faced with the needs to cut meat from carcasses, early humans in Africa discovered how to shape stones into cutting tools. From that one innovation, a whole history of human development springs. Neil tells the story of the Olduvai stone chopping tool with contributions from flint napper Phil Harding, Sir David Attenborough and African Nobel Prize winner Dr Wangeri Maathai. Producer: Anthony Denselow.