Microevolution
This is both a necessary step in covering the gamut of arguments in favor of evolution and the step that will least impress dyed-in-the-wool Creationists. Dawkins does a good job of explaining some ingenious experiments that demonstrate just how rapidly evolutionary change can occur. He describes a decades-long (and still ongoing) experiment involving E. coli bacteria, and another involving wild guppies in South America. Both experiments show conclusively that natural selection exerts powerful influence on the development of species.
Here’s the problem: the cleverest Creationists have already embraced so-called “micro-evolution;” that is, change within a species, or change into species still very closely related. The Creationists made quite a big deal out of rapid evolution in discussing Darwin’s finches in the recent documentary film The Voyage that Shook the World. Their argument, in short, was that the incredible variety of birds we see today could be the results of rapid evolutionary expansion from only a few species left over after Noah’s Flood. (Yes, it’s a stupid argument, but one that has at least a whiff of plausibility.) So, while Dawkins is right to lay out this evidence, it won’t in and of itself be much of a convincer. Snarky Creationists would only be shut up (and maybe not even then) with an experiment that demonstrated the emergence of radical new features like, say winged mice, or grasshoppers with spines.
Dawkins warns the reader not once but twice in this chapter, not to read it while tired or sleepy. Now, to me this seems like an awkward way to apologize for a boring passage to come, but I didn’t find it either boring or all that difficult to understand, so I think this warning would have been better left out.
Finally, I had to laugh aloud when reading Dawkins complain about reading a pamphlet in his doctor’s waiting room warning that bacteria were “clever” and could “learn” to cope with antibiotics. The same guy who talked about plants offering “bribes of food” to bees and of flowers having strategies to attract insects has little room to criticize some medical writer talking about clever bacteria!