The remarkable story of a solitary wolf living against the odds and his close bond with renowned wildlife photographer Cheryl Alexander.

For most of its existence, planet Earth has been a brutal, inhospitable, toxic nightmare, until a half billion years ago when – KABOOM! – life suddenly appeared. First Animals, a new documentary from The Nature of Things, takes you back to the Cambrian Explosion through newly-discovered fossils that tell us more about our own origins.