This sequel to "Dinosaur!" takes a journey through millions of years from the beginnings of life on Earth to the creatures we know today. It is 3500 million years since the earliest known life-forms existed, but human beings appeared on the scene only 100,000 years ago. To help put the story in perspective, the book explains the processes which enable us to measure geological time, how fossils help us to understand the creatures of the past, and how the principles of evolution have been developed since Darwin's groundbreaking work in the Victorian era. Further chapters take readers from the simplest forms of bacteria, through early forms of marine life, land-dwelling vertebrates and the age of dinosaurs and primitive birds, up the great apes and the appearance of the first humans.