Where did human beings come from? Why is there such a huge variety of living things on Earth? The theory of evolution answers these and many more questions we may have on where we come from and how life has developed. This fascinating book looks at the historical controversies that surround the theory of evolution and tells the stories of the scientists who worked on the theory. It also examines how the theory of evolution was arrived at, how it was tested and what impact the theory has had on our understanding of science today.