At the end of the Ice Age, one of the most important parts of human existence was finding enough food to survive. Taking a pestle from Papua New Guinea as an example, Neil MacGregor, Director of the British Museum, asks why our ancestors decided to cook foods, rather than just eat them raw. The answer provides us with a telling insight into the way early humans settled on the land. Including contributions by food writer Madhur Jaffrey, campaigner Sir Bob Geldof and archaeologist Professor Martin Jones. (Duration: 14 mins)