The Incredible Human Journey

When our species first arrived in Europe, the peak of the Ice Age was approaching and the continent was already crawling with a rival: stronger, at home in the cold and even (contrary to the popular image) brainier than us. So how did the European pioneers survive first the Neanderthals and then the deep freeze as they pushed across the continent?

Alice Roberts reconstructs the head of the 'first European' to come face to face with one of our ancestors; she discovers how art became crucial for survival in the face of Neanderthal competition; and what happened to change the skin colour of these European pioneers.

Finally, spectacular new finds on the edge of Europe suggest that the first known temples may have been a spark for a huge revolution in our ancestors' way of life - agriculture.

Alice looks at our ancestors' seemingly impossible journey to Australia. Miraculously preserved footprints and very old human fossils buried in the outback suggest a mystery: that humans reached Australia almost before anywhere else. How could they have travelled so far from Africa, crossing the open sea on the way, and do it thousands of years before they made it to Europe?

The evidence trail is faint and difficult to pick up, but Alice takes on the challenge. In India, new discoveries among the debris of a super volcano hint that our species started the journey much earlier than previously thought, while in Malaysia, genetics points to an ancient trail still detectable in the DNA of tribes today.

Alice travels deep into the Asian rainforests in search of the first cavemen of Borneo and tests out a Stone Age raft to see whether sea travel would have been possible thousands of years ago, before coming to a powerful conclusion.

For Stone Age people, reaching North and South America seems impossible - on each side vast oceans, and to the north an impenetrable ice sheet that covered the whole of Canada. So how did the first Americans get there?

Dr Alice Roberts discovers evidence for an ancient corridor through the Canadian ice sheet that may have allowed those first people through. But there are problems - in particular some very ancient finds in southern Chile seem to suggest a very different way in to the Americas. Amazingly, an ancient human skull discovered in Brazil even points to an Australasian origin of the Americans. Could a route from Australia across the Pacific have been possible? A surprising answer to the problem eventually comes from a Canadian forensic scientist more used to solving murder cases.