Secular Sunday: Case for a Creator: Chapter 3, Part 4
Moving on to the next icon of evolution, number three: Haeckel’s embryos. As a refresher: Ernst Haeckel proposed that many animals in their embryonic stages look indistinguishable from each other, which is evidence of common descent. Haeckel’s work was put forth in a series of drawings showing the developmental stages of the animals.
The short version of Wells’ argument, again, is a long-winded “nuh uh.” He states that the drawings faked the similarities, and that at the early embryonic stages animals look nothing alike.
It is true that Haeckel did exaggerate the similarities between the embryos in his drawings, and so his drawings should not (and consequently do not) appear in modern scientific texts. But Wells would like to claim that embryology does not support common descent at all if you actually look at the embryos.
So let’s see. Below is a dolphin, cat, and human embryo, not in that order. Can you tell which is which?
Look, this entire section is a retread from Wells’ own book, Icons of Evolution, which has already been thoroughly rebutted by PZ Meyers (author of the fantastic Pharyngula blog) here. The conclusions:
- Evolutionary theory is not founded on Haeckel’s observations or theories.
- The similarities between vertebrate embryos are real.
- Evidence for common descent lies in the unity of form and process.
I won’t devote any more time to this since it’s addressed on TalkOrigins.1
Instead I’m going to focus on another part of this section, Wells’ treatment of homology. Strobel explains:
Earlier in our interview, Wells had brought up another category of evidence for universal ancestry: homology in vertebrate limbs. I remember as a student seeing the drawings depicting the similar bone structures in a bat’s wing, a porpoise’s flipper, a horse’s leg, and a human’s hand. I was told that even though these limbs have been adapted for different uses, their underlying similarity — or “homology” — is proof that they all share a common ancestor. [pg 52]
This is, for once, an accurate description of evolutionary theory and terms. And how does Wells handle that? Basically by saying “That could have been a designer, too!”
Yes, Wells, it could have been. And it could have been puked out by the cosmic turtle. It “could have been” anything. The issue is, what does the evidence say it was?
Wells detours around this question by creating, or rather repeating, a straw man argument. He brings up a biologist named Tim Berra, who according to Wells, said that if you look at cars, from one model year to the next you can see “descent with modification.” Wells calls this “Berra’s Blunder” and explains:
“Far from demonstrating his point, the illustration shows that a designer could have been involved,” Wells said. “These successive models of the corvette are based on plans drawn up by engineers, so there’s intelligence at work to guide and implement the process. If you wanted to demonstrate that the similar features resulted from a Darwinian process, you would have to show that once you somehow got an automobile, the natural forces of rust, wind, water, and gravity would turn one model into its successor.” [pg 53]
Wells is half right here, and half totally wrong. If Berra actually made that analogy, then I would agree with Wells in calling that a blunder, because it opens up exactly the line of argument that Wells has used. It is a terrible analogy, because as Wells points out, we have ample evidence that cars are created by designers, and no evidence of cars ever occurring via natural processes.
Where Wells gets it wrong, however, is in claiming that because we know a car has a designer, therefore everything does. Again, we know a car has a designer because we have mountains of evidence that cars are designed. We can look at the blueprints, meet the engineers, visit the factories, ask questions as to how and why certain modifications were made. There are no cars that occur via natural processes to be studied.
But when it comes to biology, we have ample evidence that these things DO occur naturally, and no evidence of a designer whatsoever, aside from that which is imposed on nature by the human mind. The human mind has evolved to be attuned to recognizing patterns, but sometimes (even “often”) recognizes patterns where none exist. There’s even a term for this: it’s called pareidolia.
So Wells and I agree that Berra was wrong to make that analogy, because they are not analogous. It’s also important to note that Wells misrepresents descent with modification, indicating that a proper Darwinian analogy would have outside forces acting on the car, altering it until it became the next model of car.
That is equivalent to saying that babies are formed by their parents transmogrifying into children, and is a common misunderstanding of evolutionary theory. It’s related to “if evolution is true, why can’t I just sprout wings right now? It would certainly be advantageous to me!” (And yes, I’ve heard that one.) Evolution does not work on an individual organism, it works between the generations. The alteration doesn’t occur to me, it occurs at the development stage of my progeny.
The only way the car analogy works would be if the cars could be capable of reproducing, either sexually or asexually. They are not, and so the analogy is, as Wells says, a “blunder.”
Wells then argues that similar genes often give rise to different features. He notes that the gene for “eyes” in various organisms is similar, yet the eyes of an octopus, a mouse, and a fruit fly are vastly different than each other. There are two issues here: “similar” genes are not “identical” genes. We still don’t know everything we can about genetics, and it could be that a single base pair, out of the millions in each gene, makes the difference between a single-faceted eye and a compound eye. And as I explained in my post about the Newsweek article a couple weeks ago, even if the genes were identical, it could simply mean that chemical triggers to turn compound eyes “on” in fruit flies stay “off” in octopi.
“In fact [says Wells], it’s so similar that you can put the mouse gene into a fruit fly that’s missing that gene and you can get the fruit fly to develop its eyes as it normally would. The genes are that similar” [pg 54]. This is actually true. I think that’s awesome. Of course, Wells claims that this behavior is completely baffling to “the experts,” and they have no explanation for it.
An odd claim, given that when I google “mouse fruit fly eye” the very first link is an expert explaining why this occurs. Although he describes the biological mechanism a little bit differently than I did in the Newsweek post (which means, certainly, that I got it a little wrong). According to him, the fruit fly and mouse both have “make eye” programs somewhere in the genome as they are development. What Wells calls the eye gene, if I’m interpreting the PBS article correctly, is actually a gene that tells the developing embryo “Run program: ‘make eye’.” In this example it’s not a chemical trigger acting on a gene, but rather a gene itself acting on another gene.
At any rate, in no way is this inherently indicative of a designer, and Wells seems to realize this. He says, essentially, “We have no proof there’s a designer — but they have no proof there ISN’T!” Which, as I’ve explained before, is not how science works. He does the same thing when Strobel, wearing what he considers his Skeptic’s Hat (I picture a beanie with a propeller), asks him about the close genetic similarities between humans and apes, and Wells throws out the same thing: “That could be a designer!” Sure, it could be, but there’s no evidence to believe that it is. Wells still hasn’t bothered to show a single shred of evidence that there’s a designer, the best he’s got is “I don’t see why NOT!”
And then Strobel comes up with an utterly retarded analogy.
“Let me see if I understand you. If I were to chemically analyze that street and sidewalk,” I said, pointing out the window, “I’d find they would be identical or very similar. They’d both be made of concrete. But that wouldn’t mean that they shared a common ancestor — say, a path for a golf cart — that got wider and more substantial over millions of years. A better explanation would be that there was a common designer who decided to use basically the same materials to construct similar, but functionally different, structures.” [pg 55]
Anyone else feel queasy after reading that? Or notice that this is exactly the argument Wells calls “Berra’s Blunder”? And yet Wells agrees that this is an accurate way to think of it. “It sounds ridiculous…but it’s not any more outlandish than some of the claims for biological evolution.”
Yes it is. Yes it is. Holy shit, YES IT IS.
Same issues with this analogy as before:
- Concrete paths of any kind have not been observed to form naturally; biological structures have.
- We can look at the blueprints and in many cases meet and speak with the designers of concrete paths; not so with biological structures.
- Concrete paths cannot produce offspring; biological structures do.
Need I go on?
Strobel, of course, is totally convinced that Wells is talking perfect sense, and concludes “that Darwin was wrong: examining embryos different creatures in their early stages does not yield support for his theory. And the undeniable similarities between some vertebrate limbs certainly doesn’t distinguish between design or descent as a cause. once again, the persuasive power of the evolutionary icons had been deflated” [pg 55].
So once again, Strobel comes out of this concluding what he wanted to conclude, even though the actual evidence indicates quite the opposite. No reason to be surprised at this point, I’m sure.
Next time we talk about this book, it’s icon #4: Archaeopetryx.
- In fact, most of this book could be easily rebutted by just linking to various TalkOrigins pages, being that these are all very, very common creationist canards and as such have been thoroughly, thoroughly refuted. I’m not doing that for the most part, because it’s important, to me, that I explain as much as I can in my own words, lest I be accused of just believing evolution “blindly.”↩