Richard Dawkins’ 2009 book The Greatest Show on Earth: the Evidence for Evolution is an excellent explanation of what Evolution is, how it works, and why it must be true. It is written with clarity for the non-specialist, and should be accessible to any college-educated reader. In a few places Dawkins relies a little too much on references to his other, copious writings, but he has mostly managed to find a good balance between length and readability.

The book touches on many aspects of evolution, from radiometric dating to continental drift to genetics to the domestication of plants and animals. He aptly describes Evolution as an “improbability pump,” a process by which many small steps, each as probable as another, can, over time, produce hugely unlikely results. It makes me want to read his 1997 book Climbing Mount Improbable. Through it all, Dawkins refers to Creationists as “history-deniers,” meaning that they simply refuse to face plain facts.

I was especially struck by Dawkins’ rabbit example (pp. 24-25). He asks the reader to imagine a line of female rabbits, from daughter to mother, to grandmother, to great-grandmother, etc., stretching back for millennia. No matter where we look along this line of descent, any individuals within a few generations of each other will always be the same species. Any differences within a handful of generations will always be negligible, and there will never be any sharp or sudden break. Yet, if we compare individuals separated by thousands of generations, they will be quite different from each other, even distinct species. At the far ends of the chain are a modern-day rabbit and small, shrew-like creature that was the ancestor not only of rabbits, but of all mammals. At any point along the line of descent, separate populations of a given form can take different directions, creating different branches on the family tree.

The rabbit example is important because it addresses some of the most common misunderstandings of Evolution. Creationists too often believe that Evolution means that a horse one day gave birth to a zebra, or that chimeras such as the now infamous and ridiculous “crocoduck” should turn up in the fossil record. They insist that speciation must be sudden and dramatic, and expect an entire species to change in the same way at the same time. The rabbit example helps replace these misconceptions with a more scientific understanding of how Evolution works.

– Jim Dugan