Richard Dawkins begins The Greatest Show on Earth with a short history of his writing career. He explains that all of his previous books have naively assumed the fact of evolution, which meant that he never got around to laying out the evidence that it [evolution] is true. This shouldn't be too surprising: science is an edifice of tested assumptions, and just as physicists must assume the truth of gravity before moving on to quantum mechanics, so do biologists depend on the reality of evolution. It's the theory that makes every other theory possible.Yet Dawkins also came to realize that a disturbingly large percentage of the American and British public didn't share his enthusiasm for evolution. In fact, they actively abhorred the idea, since it seemed to contradict the Bible and diminish the role of God.