In 2001, scientists announced an amazing discovery: the oldest skull of a human ancestor ever found. The 3½ million year old fossil was remarkably complete, and unlike any previous fossil find. Its discovery - by a team led by Meave Leakey of the famous Leakey fossil-hunting family - has revolutionised our understanding of how humans evolved.

The great mystery of our evolution is how an ape could have evolved into the extraordinary creature that is a human being. There has never been another animal like us on the planet. And yet ten million years ago there was no sign that humans would take over the world. Instead the Earth was dominated by the apes. More than 50 different species of ape roamed the world - ten million years ago Earth really was the planet of the apes. Three million years later, most had vanished. In their place came something clearly related to the apes, but also completely different: human beings!