Steve travels back 3.8 billion years to when life began. Journeying round the oceans, he explores life's first laboratory and discovers how the incredible variety of sea creatures arose, from the first microbes to hagfish and dolphins.
Steve tracks the pioneer life forms as they emerged from the seas and evolved adaptations to make them ever better able to cope with life on land, from the searing heat of the deserts to the icy polar wastes.
Animals crawled on to the land 500 million years ago, but it was another 100 million years before life finally became airborne. Just four kinds of animals achieved the miracle of flight. Insects led the way, but their story is still shrouded in mystery.
The greatest evolutionary challenge faced by living things has been each other! From cunning carnivores to sex crazed elk, Steve reveals how the relationships between living things can drive evolution itself - with some truly bizarre results.