Dawkins has a nice sense of irony, deployed without mercy on the opponents of evolution. If the creationists think the earth is less than 10,000 years old, rather than 4.6 billion, he asks, shouldn’t they assume, by the same measure, that North America is less than 10 yards wide? The book is even more enjoyable when Dawkins forgets the creationists and launches into evolutionary explanations, whether of the hippopotamus’s long-lost cousin the whale, or of the long-tongued moth that Darwin predicted must exist to pollinate a Madagascan orchid with a nectary 11 inches in length. He gives striking examples of “unintelligent design,” forced on evolution because it cannot ever start from scratch but must develop new structures from older ones.
Ah, path dependence, one of my favorite concepts that I learned of in grad school--a useful way of thinking about how the past choices or events constrain the present. Which leads to this:
The best way, in my view [the book reviewer's view], is to distinguish between evolution as history and evolution as science. Evolution is indeed a historical fact. Every living thing and every fossil-bearing rock bears evidence that evolution occurred. But evolution is not a scientific fact as philosophers of science see it. In science it plays a far grander role: it is the theory without which nothing in biology makes sense. The condition of this high status is that it cannot be the final and absolute truth that Dawkins imagines it to be; it is liable to future modification and change like any other scientific theory.Ah, there is the confusion. We know that there has been evolution--but the explanation for it is subject to change precisely because it is not faith but based on science. Science changes when new facts are found that conflict old theories or that new theories can explain that which old theories explained plus that which old theories could not explain (Einstein > Newton).
Creationist types use the debates amongst biologists and other scientists to show that evolution is just another hotly debated topic, and therefore is just a theory. And, thus, they show that they, like most of us, don't really get what science is--an exploration of the world around us that is never satisfied, not even after tenure. Which means that we can have a great deal of confidence that, indeed, evolution has occurred, but that we might develop a better explanation for it as we learn new stuff. And we are always learning new stuff.
The irony is that the super-religious folks find it problematic that scientists can and do change their minds when confronted with new facts.