Also to Jerry Coyne. Now there’s a fantasy trio that ought to send shivers of revulsion down your spine! Anyway, I was once again featured on Hovind’s “Whack-An-Atheist” series, and he once again avoided my challenge.
Way back in January, after repeated demands that I debate him, I offered a different alternative: that Kent Hovind should read a book. I even suggested one, Jerry Coyne’s Why Evolution Is True, because it’s a good general overview of the evidence for evolution, and would give him something actually said by an evolutionary biologist to sink his teeth into.
He responded by…not reading a book, but just regurgitating the same tired, false points he’s been making for decades. Come on, Kent, at the very least I expected this would compel him to get some new material! But nope, it was same ol’ same ol’.
Then he did it again yesterday. Still not reading a book, but instead digging up a YouTube video of Coyne presenting a summary of some of the concepts in the book, and whining about that with the very same slides he’s been using for years.
My god, but Kent Hovind is the laziest creationist on the circuits. It’s not a thick book, it’s written for a popular audience, it’s a relatively easy read. Reading it might have spared him from making a few ludicrous errors.
What Hovind did was focus on a tiny part of the story, which is generally a good idea, but he clearly picked the part where he thought he had a good gotcha. He drilled down into Haeckel. Coyne talked about how some embryonic features reveal their evolutionary history, like the presence of hind limb buds in dolphin embryos — retention of conserved features in development is evidence of evolution. Hovind, though, went on a familiar tirade about Ernst Haeckel, and his discredited theory of evolutionary recapitulation from the 19th century.
It’s totally irrelevant. That a scientist advanced a wrong theory about evolution 150 years ago does not change the fact that embryonic similarities are observed, that they make no sense in terms of modern function, but do make sense in the light of evolution as relics of their ancestry. It would be a bit like me attacking Hovind’s interpretation of the Bible by citing the Book of Mormon at him; I don’t think Hovind considers Joseph Smith to be a significant contributor to his ideas. Going on and on about the invalid Biogenetic Law to refute Coyne’s discussion of embryonic atavisms is basically the Wookie Defense.
Now if he’d actually read Coyne’s book, he’d have known that trying to attack him via Haeckel was inappropriate. Coyne also rejects the Biogenetic Law, as he explains in chapter 3:
This “adding new stuff onto old” principle also explains why the sequence of developmental change mirrors the evolutionay sequence of organisms. As one group evolves from another, it often adds its developmental program on top of the old one.
Noting this principle, Ernst Haeckel, a German evolutionist and Darwin’s contemporary, formulated a “biogenetic law” in 1866, famously summarized as “ontogeny recapitulates phylogeny.” This means that the development of an organism simply replays its evolutionary history. But this notion is true in only a limited sense. Embryonic stages don’t look like the adult forms of their ancestors, as Haeckel claimed, but like the embryonic forms of ancestors. Human fetuses, for example, never resemble adult fish or reptiles, but in certain ways they do resemble embryonic fish and reptiles. Also, the recapitulation is neither strict nor inevitable: not every feature of ancestor’s embryo appears in its descendant, nor do all stages of development unfold in a strict evolutionary order. Further, some species, like plants, have dispensed nearly all traces of their ancestry during development. Haeckel’s law has fallen into disrepute not only because it wasn’t strictly true, but also because Haeckel was accused, largely unjustly, of fudging some drawings of early embryos to make them look more similar that they really are. Yet we shouldn’t throw out the baby with the bathwater. Embryos still show a form of recapitulation: features that arose earlier in evolution often appear earlier in development. And this makes sense only if species have an evolutionary history.
Yeah, fallen into disrepute. So why try to play gotcha with Coyne on that point? Coyne is actually presenting a von Baerian perspective here: von Baer, who did not accept evolutionary theory, had observed how similar early vertebrate embryos were to one another. That fact is not in dispute. I can go into my lab right now and pull up slides of sectioned and stained chick, mouse, and frog embryos that all show these shared developmental features. Pharyngeal pouches are a real thing! You can’t make them disappear by citing someone’s flawed pet theory for them.
Bonus! There’s a footnote in the passage above, and here it is.
Creationists often cite Haeckel’s “fudged” drawings as a tool for attacking evolution in general: evolutionists, they claim, will distort the facts to support a misguided Darwinism. But the Haeckel story is not so simple. Haeckel may not have been guilty of malfeasance, but only of sloppiness: his “fraud” consisted solely of illustrating three different embryos using the same woodcut. When called to account, he admitted the error and corrected it. There’s simply no evidence that he consciously distorted the appearance of the embryos to make them look more similar than they were. R.J. Richards (2008, chapter 8) tells the full story.
Coyne is a little too generous here. I think Haeckel demonstrated an over-zealous commitment to his theory, and while it may not have been conscious, he did bias his examples to favor an incorrect idea. He is correct, though, that it is really common for creationists to dig up the dead corpse of poor old Ernst Haeckel and wallop on it for a bit while telling everyone they’re defeating Darwinism. They aren’t.
By the way, the bit in the Origin where he discusses “the strongest single class of facts in favor of change of forms”, consists of Darwin discussing, among other things, von Baer’s observations of embryos, not Haeckel’s. Hovind misses the mark again, but I don’t think he’s read the Origin, either.