It was only a few days ago now that I posted The Scars of Eye Surgery about Brian Thomas’ article Do Eyes Carry ‘Scars of Evolution’? Mr Thomas has decided that he needs to write on the same article again, apparently because there really isn’t much evolution/creationism related going on right now.* The result: Eye Evolution: Assumption, Not Science. In the circumstances, that describes much better his reading of the subject than the actual thing.
The article that is the focus of both DpSUs is Trevor D Lamb’s Evolution of the Eye article at Scientific American (you’ll need a subscription to read much). The first DpSU attacked Lamb’s assertion that the eye carries the ‘scars of evolution’ – that is, evolution has caused the human eye to be different (ie not as good) compared to what it could have been if it was literally designed as the creationists claim. In my post I gave a summary of eyes as used in the ‘controversy’ between evolution and creationism – here’s an excerpt that is also relevant to this post:
Eyes are a common topic in the great “controversy” between creationism and evolution. The earliest origins seem to lie in a certain oft-misquoted line in On the Origin of Species, where Darwin apparently states that the idea that the eye was evolved is “absurd”… until you read the rest of the paragraph. Creationists and their opponents alike have called the human eye incredibly and horribly designed respectively to further their points. Also, we know a route that they eye as it stands could have taken to evolve incredibly quickly – in merely a few hundred thousand years – given the right conditions.
Today’s post alleges that the eye could not have evolved at all, and attacks Lamb for “logical fallacies.” Here we go again…
First, Lamb granted god-like intelligence to an inanimate force he termed “selective pressures.” He wrote, “As body size increased, so, too, did the selective pressures favoring the evolution of another type of eye: the camera [vertebrate] variety.” But only an intelligent agent—not passive, unthinking environmental factors—could fashion the massive collection of interdependent parts that form vertebrate eyes. Lamb also wrote that “natural selection…tinkers with the material available to it,” when in reality only persons can “tinker.”
Only people can tinker? If we want to talk semantics here, the definition of ‘tinker’ is “The act of repair or invention.” If you bust up an ants nest they’ll try to repair it (depending on the species and the severity and kind of damage), and Thompson’s experiment certainly produced a new invention.
Semantics aside, the paragraph suggests that either a) the Creationists at the ICR couldn’t spot a metaphor if it danced past them in a green poncho singing It’s All About The Pentiums or b) they don’t think their audience can. Is this bad metaphor-spotting skill the root of the Young earth Creationist movement, or just a additional problem brought on by the severe cognitive dissonance required to maintain the belief? One day we may know for sure. Until then…
The article made eye evolution easier to imagine by excluding the complicated design details of eye anatomy. How, step by step, would “selection” have precisely positioned the 12 muscles that adroitly move the eyeball in its socket, including the one that uses a pulley to properly swivel the eyes?
This ‘pulley’ – the Trochlea of superior oblique – becomes somewhat less amazing when you realise that there is no analogous component to the circular spinning thing in the centre of man-made pulleys – it’s more like chucking a rope over a tree limb, not a particularly difficult thing for evolution to achieve. And the muscles generally? I’m guessing that Mr Thomas is ignoring their ability to happen at the same time as everything else is – perhaps with facial muscles that had the ability to alter the position of an early eye, but which over time moved behind the eye into a better position as the eye became more cup-like. The possibilities are endless.
And even if perfectly formed eyes and eye-moving muscles had somehow managed to evolve, the apparatus still would have been useless without the involuntary computations that make both the left and right eyes move in concert.
Chameleon eyes are not ‘useless,’ what is he on about? And not doing the extra computations that would be required to make the eyes move truly independently is simpler anyway – he has the wrong end of the stick here.
In addition to overlooking these vital features, Lamb gave no explanation for how “selective pressures” could have programmed the brain to convert raw light input into discernable mental images.
I’m wondering if Mr Thomas has ever been taught about the wonders of the neural net. You can teach them to read handwriting for goodness sake… (probably not mine though).
Lamb wrote, “Biologists have recently made significant advances in tracing the origin of the eye—by studying how it forms in developing embryos.” He suggested that embryonic eye development moves from simple to complicated in a pattern similar to eyeball evolution. But embryo eyes have to begin small and are therefore relatively simple at the start. Assuming, with no objective evidence, that embryonic development mirrors an evolutionary past merely begs the question of an evolutionary origin.
Ah, the alleged logical fallacy. It only is, though, if there is no ‘objective evidence’ that ’embryonic development mirrors an evolutionary past.’ I can assure you that Evo-Devo is no pseudoscience. We know ways that they eye could have evolved, after all, and the embryonic development generally follows this, even though that is not technically necessary. And, if nothing else, watching the muscles move into position in the embryo can give inspiration as to how they would have done so evolutionarily.
In telling his eye evolution story, Lamb used terms such as tinkers, diverged, proliferated, arose, arisen, favoring, insert themselves, invention, modified, emergence, and evolved—ignoring the fact that no one has ever observed unthinking, undirected “selective pressures” doing or causing any of those things. These “magic” words mask evolution’s lack of real scientific explanations for eye origins and “convey wish-like convictions that if evolutionists just believe deeply enough, their explanations must be true and someday will be true—though currently resisted by all scientific evidence.”3
Cite 3 is a not a-typical article attacking evolution for it’s “magic words.” “Any sufficiently advanced [concept] is indistinguishable from magic,”To slightly modify Clarke’s Third Law at least to those who (willingly in this case) don’t understand it. If I had the time I could go through that list and find out a place where each one has been observed. It would be more time-consuming than difficult, I should think.
You want a good explanation of how to make an eye? Watch this video.
*That’s sarcasm by the way…