Experts suspect that the dinosaurs were wiped out after a city-sized asteroid smashed into the Gulf of Mexico causing a huge crater. But until now, they haven't had any proof. In a world first, evolutionary biologist Ben Garrod joins a multi-million pound drilling expedition into the exact spot the asteroid hit to get hard evidence of the link. The team overcomes huge obstacles as it attempts to drill 1,500 metres beneath sea level to pull up rock from the Chicxulub crater. Meanwhile, paleopathologist Professor Alice Roberts travels the globe meeting top scientists and gaining exclusive access to a mass fossil graveyard in New Jersey - believed to date from the same time the asteroid hit. Alice also treks by horseback across the remote plains of Patagonia, to see if the effects of the asteroid impact could have wiped out dinosaurs across the world - almost immediately.

Dr Alice Roberts re-traces the greatest ever journey taken by our ancestors. Thousands of years ago one small group of our species, Homo sapiens, crossed out of Africa and into the unknown. Their descendants faced baking deserts, sweat-soaked jungles and frozen wildernesses and risked everything on the vast empty ocean. Within 60,000 years they colonised the whole world... How did they do it? Why do we, their descendants all look so different?

Alice Roberts tries to find out how Stone Age people reached North and South America for the first time. She finds out about an ancient corridor through the Canadian ice sheet that might have allowed the first humans through. Old finds in Chile though point to a whole different route for the first humans making it there.

Dr Alice Roberts 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.

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 their 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 from black to white.

Alice Roberts explores the latest discoveries in the study of human origins, revealing the transformation that has been brought about in this field by genetics. Traditional Palaeoanthropology, based on fossils, is being transformed by advanced genome sequencing techniques. We now know that there were at least four other distinct species of human on the planet at the same time as us - some of them identified from astonishingly well-preserved DNA extracted from 50,000-year-old bones, others hinted at by archaic sections of DNA hidden in our modern genome. What's more, we now know that our ancestors met and interacted with these other humans, in ways that still have ramifications today. Alice uses these revelations to update our picture of the human family tree.