Chapter-by-chapter thoughts on Richard Dawkins’ The Greatest Show on Earth: The Evidence for Evolution
by John C. Snider © 2009
Chapter 5: Before our very eyes
This chapter 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 in Chapter 3 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!
On to Chapter 6…!
The Greatest Show on Earth is available at Amazon.com and Amazon.co.uk.
Read my thoughts on Chapter 4.
Read my thoughts on Chapter 3.
Read my thoughts on Chapter 2.
Read my thoughts on Chapter 1.
While it is true that creationists have embraced microevolution, generally they deny that mutation/natural selection can be creative – that is to say that new structures or functions can emerge. They have abandoned the old “no beneficial mutations” argument to a more subtle one that mutation cannot generate information. On a trivial level, this is easy to disprove mathematically, but they can then claim they mean some other sort of information – The idea the a mutation can do something new, and not just do something less well. The bacteria experiment (along with numerous others that Dawkins does not mention) show that this simply is not true. New function can emerge, often without the lost of the old ones (I’d be interested to know if in this case it was due to the modification of the active site of an existing enzyme, or that some other part of the protein mutated in such a way it was able to metabolise a new substrate, or at least to do so at a biologically relevant rate (something else that has been observed). Overall, I liked the chapter, but I think Dawkins should have emphasised more strongly that mutation and selection can generate new functions.
[...] Read my thoughts on Chapter 5. [...]
[...] Read my thoughts on Chapter 5. [...]
[...] Read my thoughts on Chapter 5. [...]
[...] Read my thoughts on Chapter 5. [...]
[...] Read my thoughts on Chapter 5. [...]
[...] Read my thoughts on Chapter 5. [...]
[...] Read my thoughts on Chapter 5. [...]