Professor Alice Roberts is making a new human being - she is pregnant with her second child. But before he is born, she wants to find out what makes a human, human? What is that separates us from our closest living relatives - the chimpanzees? We share 99% of our DNA with chimpanzees and yet from the moment of birth, our lives are completely different. So are we just another animal, or is there something special about being human? Before her new baby emerges into the world, Professor Roberts sets out to explore what it is about our bodies, our genes and ultimately our brains that set us apart from our furry cousins - what is it that truly makes us human?