It was during the Ice Age that humanity as we know it was forged. Two rival species competed until only one was left standing. Steve Backshall and Michaela Strachan travel the world to discover how Neanderthals and Homo sapiens survived at a time of brutal environmental change and uncover why we, Homo sapiens, survived while the Neanderthals were wiped off the face of the Earth. Steve heads to southern Germany, which is a hotbed of early human discoveries. In the freezing temperatures of the snow-lined valleys, Steve throws himself into Ice Age life, exploring how early humans evaded the mighty Ice Age predators such as the supersized cave bears and giant hyenas that stalked the freezing wastelands. In a battle against the elements and predators, Steve discovers how Neanderthals made fire in a surprisingly sophisticated way and crafted tools so sharp you could shave with them! Meanwhile, Michaela gets to grips with the differences between Neanderthals and Homo sapiens. At the prestigious Natural History Museum, she's able to see that Neanderthals were physically stronger than Homo sapiens and by looking at their skulls can see they even had bigger brains. So why then did we as a species survive and the Neanderthals did not? The answer could lie in how both species developed technology. Steve tests out the differences between how Neanderthals and Homo sapiens hunted mega-beasts like the woolly mammoth. He tries throwing Neanderthal spears, but discovers that Homo sapiens developed a better way to hunt. Meanwhile, Michaela uncovers how one invention, the humble sewing needle, gave Homo sapiens a huge advantage — why? But the biggest turning point in our species evolution came as the Ice Age thawed and a natural disaster loomed, one that threatened to wipe out the Neanderthals.