Your Inner Fish

2. Your Inner Reptile

Episode 2 traces our hair, skin, teeth, jaws and sense of hearing back to reptilian ancestors - from ferocious beasts that ruled the Earth, to a little shrew-like animal that lived 195 million years ago.

3. Your Inner Monkey

In the final episode, Neil tracks our hands, feet, colour vision, spine and upright gait to our primate and hominid progenitors, who also passed on perhaps the most important legacy of all - a path to the human brain.