I had a couple hours to read last night, but didn’t want to start a fat novel as I’m leaving the country soon and wouldn’t want to schlep it. I thus picked up an old copy of God is Not Great, by Christopher Hitchens, which is a pretty quick read. After two nights I’m almost half done with it, but am a bit disappointed because a lot of the science is wrong or outmoded (the latter is, of course, not Hitchens’s fault), and the arguments seem pretty repetitive.
On the other hand, I realize that these arguments were badly needed at the time and made a big impact on nonbelievers and believers alike. It’s one of the books that kick-started the “New Atheism,” and the “New” bit, as I always say, was the use of scientific arguments to rebut religions faith claims. These arguments are amply in view in Hitchens’s book, and most of them are correct. And, of course, Hitch was a wonderful writer.
One of Hitchens’s arguments against creationism and its gussied-up cousin Intelligent Design is its invocation of vestigial organs like our vestigial tail, the appendix, wisdom teeth, and so on—all as evidence for evolution. There were also examples of features that were jury-rigged by evolution so that they’re not perfectly adapted to their function: things like the backwards placement of the retina in the human eye, our “blind spot” where the optic nerve comes in, and—my favorite—the placement of the recurrent laryngeal nerve.
When I pondered those examples, I realized that IDers and creationists argue that all of these features are really adaptive. The appendix, they say (correctly) contains a small number of cells that have immune functions, and the “backwards” retina of our camera eye is said by creationists to confer protection against an overload of short-wavelength light. But of course whether the immune function of the appendix outweighs the fact that it may become infected and kill you is pure speculation, as is the postulated “useful” function of the backwards retina.
And I haven’t yet heard of an adaptive explanation for nipples in human males, our wisdom teeth, the developmental sequence of our kidney, or our transitory coat of hair in utero (the “lanugo”), but I’m sure that if you look hard enough on the Internet, you’ll find IDers and creationists showing how these aren’t really “senseless signs of history”, but are actually adaptive. And if they’re adaptive, then they reflect God’s plan.
In the end, I realized that the true purveyors of the “adaptationist program” aren’t evolutionary psychologists, but creationists, who aren’t willing to admit that the vagaries of evolution has vouchsafed us with featurs that, if there was a god or a Designer, could have been designed better. Further, they don’t often realize that if a “vestigial” structure is useful in some way, that doesn’t disprove that it had an evolutionary origin. The “halteres”—balance organs of some insects—is one example. They are used for keeping a guided flight, but we know that they are the vestigial remnants of wings, derived from two of the four wings that flying insects used to have. And they’re useful!
I won’t dwell on this, as these things are discussed in detail in my book Why Evolution is True, and you can also see many examples of vestigial organs supporting evolution at Douglas Theobald’s great site, “29+ evidences for macroevolution” (there are multiple pages; vestigial organs, atavisms, and other features testifying to evolution are here).
Finally, I have never seen creationists even try to refute the biogeographical evidence for evolution, like the absence of endemic mammals, fish, and amphibians on oceanic islands (islands that rose, bereft of life, from the sea bed) as opposed to continental islands that were once connected to continents. Biogeography is the true Achilles Heel of both creationism and ID.
I’m often asked if I’ve though about rewriting or updating my first trade book, Why Evolution is True. My answer is always “no”—mainly because there’s enough evidence in that book to convince any rational person of its title’s assertion. But I suppose that if I did revise it, I would update it with more evidence for evolution, especially from fossils and molecular biology. I do present plenty of fossil evidence for evolution in the book, and also some molecular evidence. The latter includes the presence of “dead genes” (genes that were functional in our ancestors and in some of our relatives, but have been rendered nonfunctional in us by degrading mutations). Examples are our many dead “olfactory receptor genes, active in dogs but totally inactive in whales, or a dead gene that is key in synthesizizing Vitamin C in other mammals. That gene is defunct, an ex-gene that sings with the Choir Invisible, but its death doesn’t harm because we get the vitamin from our diet. I see no way that creationists or IDers can explain the fact that our DNA is largely junk, and much of that junk consists of dead genes. Loading our DNA with genes that don’t do anything, but still have to be copied during cell division and meiosis, is a lousy way to design a genome.
But now we have more such evidence, Here’s Ken Miller lecturing on some of the molecular/chromosomal evidence for evolution in humans and other primates from the structure of our chromosome 2.
I don’t mention this in my book, but it’s a convincing bit of evidence that we’re related to other primates.
There’s a lot of stuff like this, but I won’t belabor it now. The short take is that I don’t think WEIT (the book) needs to be revised because it would just pile additional evidence for evolution on the Everest of evidence that already exists. The fact is that evidence from a variety of different disciplines—paleontology, developmental biology, morphology (vestigial organs), biogeography, and molecular biology—all cohere to attest to the truth of evolution. IDers will admit of some microevolution, and even some macroevolution, but the more weaselly ones simply play a “god of the gaps” game, saying that there are adaptations that simply could not have evolved via a step-by-step Darwinian process of accumulating helpful mutations. (The bacterial flagellum used to be one, but has fallen in light of later research.)
Asserting that our ignorance proves the existence of a Designer has never been a good strategy for researchers. It is simply a “science stopper”, implicitly saying, “You don’t need to do any more research; I already know that this phenomenon is inexplicable by materialistic processes and therefore is evidence for supernatural design.” How many assertions like that have been debunked by later evidence? The answer is TONS OF THEM.
And I need hardly add that unless we have independent evidence for such a designer, we can simply ignore arguments that depend on its existence.






