The series of programmes in which Professor Steve Jones assesses the legacy of Charles Darwin 's Origin of Species.
Imprints. Fossils both intrigued and perplexed Darwin. Their mere presence seemed to provide ample evidence of "the origin", but the patchy glimpse of prehistory they provided allowed his critics to attack his theories: where, for example, was the animal halfway between a lizard and a bird? Where were the fish that first walked on the land?
This week's programme attempts to provide answers to these fundamental questions and looks for "fossilised" human behaviour that may give us clues as to how our ancestors thought.
Producers Jim Clarke and Anne McNaught