Evolution of the Eye

MonarchzMan writes:

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Could someone explain to me how an eye evolved with such complex network of enzymes and such?

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Just do some research and you'll find lots of information.Here's on place to start: Evolution: Library: Evolution of the EyeBy the way, you did know that the evolution of the eye is one of the examples given in Darwin's Origin of Species?------------------
Rrhain
WWJD? JWRTFM!

Fred Williams responds to me:

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I don't think MonarchzMan was looking for "just-so" stories to explain away the problem.

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Since we can find living animals with eyes identical to every step in the process, from photo-sensitive spot to spot in a depression to pinhole cameras to fluid filled and all the way up to the more advanced eyes, it isn't a "just so" story. Didn't you read the link I provided you? It said so right up front. It's the third sentence on the page: Why didn't you read what you were provided?

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"according to one scientist's calculations, only 364,000 years would have been needed for a camera-like eye to evolve from a light-sensitive patch."

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Where is the proper citation for this "evidence"?

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Do some research and find out. I am not here to do your homework for you. I made that clear in my original post: Do some research. I provided you a link to get you started. The field of the evolution of vision is long and varied and cannot be delineated in a 50-word missive.Get thee to a library!

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Is the author afraid someone might actually look at the math and find it to be compeltely bogus?

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Not at all.The author is writing an abstract to a popular audience. Those who wish to find out more information will do something like, oh, I don't know, actually watch the program that the abstract is describing or perhaps go to a library and look it up.The link I provided is a brief description of a segment in the PBS series, Evolution, and in particular, the episode titled "Darwin's Dangerous Idea." It's on videotape and DVD. If you go to your public library, they should be able to acquire a copy for you.

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Is this what you guys call "science"?

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Yes and no. We call it "science for the popular press." The link provided is not the entire case. It's an abstract. You do know what abstracts are, yes? Did you bother to look at the header of the section where you got your quote? Here it is, since you seem to have missed it the first time: Now, what do you think that might mean? Is it an indication that the text that follows is the entire amount of information contained or might it indicate that there is a lot more information in the full work which you need only to look at in order to find?If you want the journal articles, then point your browser to PubMed and look it up.Must we do all the work for you?

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To make matters worse, evolutionists were forced to admit that the eye must have evolved down 40 seperate, independent paths becuase of the "convergence" problem where similarities could not be explained via common decent!

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What makes you think this is a problem?Why can't the same thing evolve more than once? The reason why vision evolved more than a dozen times is not because evolutionary theory was "forced" to do so in order to maintain the theory. Instead, it was forced to do so because that's what the data said.Vision evolved and it evolved more than once.------------------
Rrhain
WWJD? JWRTFM!

Rei writes:

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I could go into all sorts of problems with the design of the eye, [...] to the "upside down" orientation of vision.

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OK...my physics is disappearing on me, but:Isn't that an artifact of focusing and not a "design" problem? That is, if you take an image and have the light rays pass through a simple lens, it necessary focuses upside down. In order to get it right side up, you'd have to add another lens or settle for the virtual image, right? This happens in telescopes, cameras, and all things that focus. Even a pinhole camera focuses the image upside down due to physics.The virtual image is right side up, the real image is upside down.Since our brains are capable of interpreting the data so that it is right side up, how is that a design flaw? It would appear to be dealing with inevitabilities.------------------
Rrhain
WWJD? JWRTFM!

Fred Williams writes:

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Again we have an evolutionist who is allowing the theory to explain both homology, and anti-homology (convergence). A theory that explains everything! I thought those kind of theories were not theories...

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Indeed, but homology and convergence are not opposites.That is, structures that have independent origins are not identical and do not have similar structure.Take, for example, the tail structures of fish compared to aquatic mammals. They share many things in common, but they have a huge discrepancy which shows that while both evolved, they did so separately:Fish tails are vertical and undulate horizontally. Aquatic mammal tails are horizontal and undulate vertically.Thus, we see how the same process, evolution, can result in similar effects through wildly different structures.You misunderstand the problem of "a theory that explains everything." It only causes a problem when trying to explain a single event that conceivably has mutually contradictory outcomes. Homology and convergence are not mutually contradictory.------------------
Rrhain
WWJD? JWRTFM!

JonF responds to me responding to Rei:

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go into all sorts of problems with the design of the eye, [...] to the "upside down" orientation of vision.

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OK...my physics is disappearing on me, but:

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Isn't that an artifact of focusing and not a "design" problem?

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No. IMHO "upside down" is not a good term ... "backwards" or "inverted" would be better. See The Inverted Retina: Maladaptation or Pre-adaptation?, which starts out with a good summary but goes rapidly downhill from there.

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Yes, but that's a different question. When Rei said "upside down orientation of vision," I understood him to mean the fact that the eye focuses the real image on the retina and that this image is upside down, requiring the brain to process the image so as to re-orient it correctly to match the other senses (so that "visual" down is in the same direction as "equilibrium" down).Yes, the retina of the mammalian eye is inverted in that the photoreceptors are placed behind the nerve cells they stimulate, thus requiring a blind spot where those nerves pierce the retina (unless you go even more kludgey and reroute all the nerves to the edge of the retina and back around the back) and reduce visual acuity due to the nerves literally blocking the light. Compare this to the cephalopoid eye where the retina is oriented the other way with the photoreceptors in front and the nerve cells behind, and thus no blind spot.But I was taking Rei's words for what they were, especially since he directly talked about the inversion of the retina: ------------------
Rrhain
WWJD? JWRTFM!