Written before The God Delusion, The Greatest Show on Earth is Richard Dawkins’ effort to put to rest any lingering doubts as to whether evolution might be “just a theory.” Dawkins assembles a case for evolution that is encyclopedic in scope, but always accessible and entertaining. He shows us, for example, how the fingernail of the human middle finger is related to the hoof of a horse. He finds what he calls “natural clocks” that track the passage of whole epochs. Dawkins is a clear and witty translator of complex scientific concepts. The book is supplemented with dozens of illustrations by the award-winning David McKean. A definite read for those interested in the darwinism versus creationism discussion.