The human eye has been used many times as proof of the impossibility of evolution. Recently an this article discusses the evolution of the human eye "One in the Eye for Intelligent Design"
Now the normal attack on the Eye and Evolution usually quotes Charles Darwin himself who easily admitted the human eye would be challenging to explain through evolution, but usually his comments are taken out of context, quote mining, something Creationists/Intelligent Design proponents are very good at! The Panda's Thumb reminded me of his entire discussion on the eye:
To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree.
Creationists/Intelligent Design proponents tend to leave off this part:
Yet reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist; if further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case; and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real. How a nerve comes to be sensitive to light, hardly concerns us more than how life itself first originated; but I may remark that several facts make me suspect that any sensitive nerve may be rendered sensitive to light, and likewise to those coarser vibrations of the air which produce sound. (Darwin 1872, 143-144)
There is more and you can read it
here if you like.
Of course this won't settle the whole discussion because William Dembski, in response to some other material about the evolution on the eye just cracked me up with his response. Now before you read this please remember that the Discovery Institute doesn't accept the fossil record as being a valid source of scientific information. They love to point at gaps, whine about radiological dating, and generally ignore anything about fossil they dislike. So what does one of their poster child say
here on his own website? "
Urbilateria — more biological constructs of the imagination. Where is the actual fossil evidence for these?" Does anyone else see the humor of asking for fossil evidence after spending so much time denigrating it. Plus, as anyone who has actually LEARNED anything about fossils knows that soft tissue fossils, such as an eye, are nearly impossible to find because the eye isn't part of the body that tends to become fossilized. So not only is he asking for something he will ignore if someone dropped it in his lap, but he should know that it's a rhetorical question anyway.
What I did enjoy as well, on Dembski's Uncommon Descent blog was the link to the article by Arthur V. Chadwick used to refute even the remote possibility of the eye evolving according to current theories. Dembski doesn't mention Chadwick by name, but here are a couple of things you might like to read:
This is form the very first paragraph of his paper:
"In the absence of physical evidence for the evolution of complex systems and in the absence of evidence for any increase in the information content of existing complex systems, a belief in the theory of organic evolution remains a matter of pure faith. Lacking physical evidence for increase in information content of any complex system, another theory of explanation of origins - Special Creation - has scientific precedence because it does offer an explanation for origins that comports with the data."
Hmmm I think we have a prime example of someone who has already made up his mind and will fit the evidence to his singular point of view regardless of minor details like facts. Here is part of his closing:
"To argue that they came from Precambrian forms that were not preserved because they had no hard parts is to argue again from the ABSENCE OF EVIDENCE. The absence of evidence, in science has to be construed as the evidence of absence. There is no Precambrian evolutionary sequence because there was no Precambrian evolution. Evolution as an explanation for the existence of complex living systems is a religious view held by those who wish the world to have no Originator (meaning – Huxley 1937, p. 312). Trilobites and all other forms appear on the scene as fully formed, fully competent organisms, period. It is past time to replace the theory of organic evolution with a theory that can explain the data. The only theory with explanatory value for the origin of information is the theory of Special Creation. I make no apology for choosing to place my faith in the existence of a Master Designer, a position that is consistent with the clearest interpretation of the evidence available in the Geologic Record, consistent with the clearest reading of the Book of Genesis, and a faith that is positive, uplifting and full of hope for the future."
Gotta love the consistency. Not only does Chadwick use a 1937, and highly suspect, definition of evolution, but he declares his theory as the only theory with explanatory value. Bold statements from someone whose paper doesn't seem to prove his position in any way.
By the way Urbilateria, if you were wondering, is the hypothetical last common ancestor of protostomes and deuterostomes. yes, hypothetical, which of course means it hasn't been proven. But rather than say it's a construct of the imagination, I believe it's better to say this is a hypothesis that is undergoing further research. At one time the Earth going around the Sun was hypothetical. Personally I just think Dembski is jealous because his pet imaginary construct, Specific Complexity, and its overarching construct, Intelligent Design, hasn't yet reached the plateau of being hypothetical. Right now it's just an idea, a concept, a thought. At least the Urbilateria is being investigated by real scientists, you know the ones that do real science work and publish in real scientific journals.