Professor Alice Roberts journeys 40,000 years back in time on the trail of the great beasts of the Ice Age. Drawing on the latest scientific detective work and a dash of graphic wizardry, we bring the Ice Age Giants back to life. The series begins in the 'land of the sabre-tooth'; North America, a continent that was half covered by ice that was up to two miles thick. Yet this frozen land also boasted the most impressive cast of Ice Age giants in the world. Across locations such as the Grand Canyon, the sands of Arizona and the coast of California, Alice traces the movements of Ice Age beasts like bear-sized sloths, vast mammoths and the strange beast known as the glyptodon. These leviathans all have one thing in common: they were stalked by the meanest big cat that ever prowled the Earth, armed with seven-inch teeth and hunting in packs - Smilodon fatalis, the sabre-toothed cat.

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.

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?

Dr Alice Roberts asks one of the great questions about our species: are we still evolving? There's no doubt that we're a product of millions of years of evolution. But thanks to modern technology and medicine, did we escape Darwin's law of the survival of the fittest? Alice follows a trail of clues from ancient human bones to studies of remarkable people living in the most inhospitable parts of the planet and the frontiers of genetic research, to discover if we are still evolving - and where we might be heading.

Even after thousands of years of ice crushing the northern hemisphere and temperatures of 20 degrees lower than those of today, many of the great giants of the ice age still walked the earth. It was only when the world had warmed up again that mammoths, woolly rhinos, sabre-toothed cats, giant ground sloths and glyptodonts finally became extinct. Professor Alice Roberts sets off on her last voyage back to the Ice Age to discover why.