Evolution of the eye? The myth goes on...

In another thread, Rrhain links us to a page on the PBS website's "evolution of the eye". The following excerpt is from that site :"Here's how some scientists think some eyes may have evolved: The simple light-sensitive spot on the skin of some ancestral creature gave it some tiny survival advantage, perhaps allowing it to evade a predator. Random changes then created a depression in the light-sensitive patch, a deepening pit that made "vision" a little sharper. At the same time, the pit's opening gradually narrowed, so light entered through a small aperture, like a pinhole camera.

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Every change had to confer a survival advantage, no matter how slight. Eventually, the light-sensitive spot evolved into a retina, the layer of cells and pigment at the back of the human eye. Over time a lens formed at the front of the eye. It could have arisen as a double-layered transparent tissue containing increasing amounts of liquid that gave it the convex curvature of the human eye.

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In fact, eyes corresponding to every stage in this sequence have been found in existing living species. The existence of this range of less complex light-sensitive structures supports scientists' hypotheses about how complex eyes like ours could evolve. The first animals with anything resembling an eye lived about 550 million years ago. And, 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."BTW, they forgot to end the article with "... and they lived happily ever after." Naturalists believe to have "plausible scenarios" for the eye evolution - the above is just one such 'story'. Yet, what's worse is that many Christians - even mature ones with scientific training - get caught up discussing these speculative scenarios. Why is near-sightedness so prevalent (no pun intended)?Joralex

Duplicate thread; thread found at:http://EvC Forum: Evolution of the Eye -->EvC Forum: Evolution of the EyePlease join us there, Joralex. Don't split the topic by starting two threads, your input there would be appreciated on the other thread. Right now, Fred's the only one really defending the creationist position, and he's doing a really poor job of it - he's pretty much abandoned critiquing Nilsson and Pelger's paper after having it pointed out to him that what he wrote about the paper wasn't true at all. He's also had his web page shot down, and is yet to respond.------------------
"Illuminant light,
illuminate me."

"Please join us there, Joralex. Don't split the topic by starting two threads, your input there would be appreciated on the other thread. Right now, Fred's the only one really defending the creationist position, and he's doing a really poor job of it - he's pretty much abandoned critiquing Nilsson and Pelger's paper after having it pointed out to him that what he wrote about the paper wasn't true at all. He's also had his web page shot down, and is yet to respond." I think Fred's doing a splendid job. The problem, a common one, is that evolution advocates are usually so caught up in their faith that they couldn't see a good point if it came up and bit 'em on the nose.

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BTW, I saw that other thread and I thought long and hard before starting this new thread - I believe this thread is merited (however, I could be mistaken).

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I'll wait for another opinion - if that's okay with you.

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Joralex

Joralex responds to me:

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Why is near-sightedness so prevalent (no pun intended)?

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Lots of reasons. While there is a physiological aspect to vision, there is also an environmental aspect, too. Those who spend their days in close-vision tasks are more likely to become nearsighted than those who have a wider visual range.But for the physiological aspects, since we have developed ways for those who have poor vision not to be handicapped by it, it has essentially become a neutral variation.------------------
Rrhain
WWJD? JWRTFM!

I thought only evo's were allowed to use sarcasm on this board. Oh well. The speculative scenarios are supported by eye designs that are around today. If you are looking for transitional forms of the eye, look to extant organisms in nature today. In one respect you are right. It is a "story" in some sense. No scientist worth his grit would say with certainty that the scenario is 100% fact. Hence the use of the words "could have", "according to one scientist's calculations", and so forth to frame it in a hypothetical framework. If you have a competing theory lets here it. However, it would require the same level of evidence (every stage seen in organisms today) as the above scenario cites.

"Lots of reasons. While there is a physiological aspect to vision, there is also an environmental aspect, too. Those who spend their days in close-vision tasks are more likely to become nearsighted than those who have a wider visual range.

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But for the physiological aspects, since we have developed ways for those who have poor vision not to be handicapped by it, it has essentially become a neutral variation." I'm afraid you've misunderstood.

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The 'nearsightedness' that I was referring to is intellectual in nature. What I meant was that addressing these speculative evolutionary scenarios misses far more fundamental issues - issues that cut to the core of feasibility.

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My comment was that even mature Christians with good thinking skills often times get caught up in this speculative nonsense (I've fallen more than once!).

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Try again, Rrhain.

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Joralex

Didn't you notice that he hasn't responded to a single point I've raised in a long time, despite responding to other people? Check it out! If you would like to, you can take over for him, because as of now - I'll let you in on something - I'm feeling rather cocky in relation to that thread since he couldn't answer the points. Back to your original post, myopia. First off, I'll snidely turn it back on you and ask why a creator would create myopia. Original sin, perhaps? God: Let us make them have difficulty reading signs that are far away!Of course, that ignores the fact that God says he won't punish children for the sins of their parents, but the whole bible is readily contradicted on that point.Secondly, I'll ask: how common is myopia in animals? Humans have been rather weak in related selection factors for the last 10,000 years or so, and especially these past few centuries. For example, the lack of giant predators chomping up people across Eastern Europe, and the working of many people in less long-range-vision intensive tasks than hunting, makes humans a rather poor example. For the most part, animals other than humans *do* have a low rates of visual defects in their population. In fact, those with the most intense vision requirements (such as predatory birds) have a very low incidence of defects.In humans, the chief selective factors have gone towards intelligence, dexterity, vocal capacity, and audio frequency response; things like long range vision and smell have more gone by the wayside.------------------
"Illuminant light,
illuminate me."

I thought only evo's were allowed to use sarcasm on this board. Oh well. Hey, I gotta have some fun. The speculative scenarios are supported by eye designs that are around today. If you are looking for transitional forms of the eye, look to extant organisms in nature today. I don't think so. You are assuming what you need to demonstrate - that these 'extant organisms' contain evolutionary stages of a "fully-evolved eye" (whatever the heck that means).In one respect you are right. It is a "story" in some sense. I'm afraid I meant it in the more extreme sense - a 'story' as in,
'Once upon a time there was this lovely princess...' No scientist worth his grit would say with certainty that the scenario is 100% fact. Hence the use of the words "could have", "according to one scientist's calculations", and so forth to frame it in a hypothetical framework. Could'a ... would'a ... should'a ...If you have a competing theory lets here it. However, it would require the same level of evidence (every stage seen in organisms today) as the above scenario cites. As I have made it known that I'm a fundamentalist, Christian YEC, I would have thought that my 'competing theory' would be well known : GOD!

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So, you believe that the eye evolved, right? Stay tuned...

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Joralex

Joralex So how do you suppose God was able to do it? Why did he give us such poor eyesight? You cannot even define God so how can you know that God created anything? All you offer is your OPINION and nothing more.

I'll ignore the insults, and head straight for the argument. What is the structure of the eye of a flatworm like? (Answer: A simple bundle of light-sensitive cells, surrounded by pigmented cells, and covered in a thin translucent layer - Nilsson and Pelger's starting point. This type of an eye is called an "ocellus". Some mollusks also have a lens on this ocellus, made of the same type of cells as are the protective membrane on similar relatives. Of course, no ocellus can form a very good image. The ocellus becomes duplicated in the compound eye, which is an the advantage for an animal that doesn't have a lot of room to spare (like an insect) of only covering the surface. For a larger animal, fewer numbers of deeper eyes allow more separation from the lens, enabling the formation of a better image. There's no clear-cut point between an ocellus and a camera-eye, so it seems silly to say that one couldn't have evolved; the only difference is how much separation you put between the light sensitive layer and the lens. Of course, camera eyes tend to (but not always) have a variety of other elements designed to help out in different environments - if you'd like to go ID on any of them, be my guest (the ciliary body, the iris, the nerves, etc). But the basic morphometry of the eye is pretty simple to evolve, you're not going to have much luck on that front.------------------
"Illuminant light,
illuminate me."

Then why have you made so many posts in this thread without specifying what these more fundamental issues are?

Or like "In the beginning, God created the heavens and the earth"?I find it endlessly hilarious of creationists to attack evolution as a fairy tale and then promote their own fairy tale in its stead.

The Bible......... the myth goes on.......

Joralex responds to me:

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What I meant was that addressing these speculative evolutionary scenarios misses far more fundamental issues - issues that cut to the core of feasibility.

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I'm afraid I don't understand. You're asking about feasibility and when presented with a study in feasibility that works and actually bears physical evidence in the biological record, you claim it is infeasible.Methinks we have seen a fancy version of a typical creationist tactic: Claim that X does not exist. When X is presented, change arguments and claim that it isn't an example of Y and hope to high heaven nobody notices that you didn't ask for Y in the first place.If what you want is a "feasible" method of eye evolution, then you have been given one.Now what do you want?------------------
Rrhain
WWJD? JWRTFM!

"Joralex So how do you suppose God was able to do it?" "It"? What is "it"?Why did he give us such poor eyesight? God gave us perfect eyesight. Ever hear of the 'Fall'? Of 'decay' due to this? You cannot even define God so how can you know that God created anything? Says you. God has revealed enough of Himself through Scripture and in my personal life that I know exactly who He is - I'm sorry that you can't say the same.

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As for "defining Him", do you actually believe that 'words' can encompass the Creator of all that has been, is, and shall ever be - an Omnipotent, Omniscient and eternal Being? Where would words begin? At best, words can give us an extremely general idea of who He is; the rest must come from spiritual discernment and a personal relationship, often times inexpressible.All you offer is your OPINION and nothing more. So you keep saying.

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Joralex