Evolution of the Eye

Convergence is more of a problem for creation. If two organisms were "designed" for the exact same niche, how come they approach it in radically different ways, with traits that match up with a steady progression of animals from outside that niche in progressively different niches?The very fact that traits are retained along lines even as two species try to fill the same niche is a strong piece of evidence *supporting* evolution.------------------
"Illuminant light,
illuminate me."

No, the calculations and contents of the paper are no myth. The only myth involved is created by the IDiots, who don't seem to understand that much mathematical modeling can be carried out without simulation. Of course, there's no simulation, nobody except the IDiots ever claimed there was a simulation, and the link that you posted contains nothing relevant to the contents of the paper.[This message has been edited by JonF, 09-24-2003]

Yes, I am also interested in an example of how convergence or why convergence would falsify evolution? Does the fact that a thylacine wolf looks morphologically similar to a canid wolf falsify evolution though the thylacine clearly had a marsupial reproductive system and is genetically firmly placed within the marsupial lineage and not that of eutherian carnivores?

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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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As opposed to what explanatory power that creationists ramblings have?

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!

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.

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!

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Show me an example of how convergence has made phylogentic analysis IMPOSSIBLE. I would be happy to discuss it.

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Loudmouth, that is not what I asked. Let me ask again. Try to answer with a simple yes or no, then you can explain your answer. Does convergence thwart, or aid, in attempts to construct phylogenies? Yes or No.

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Here we have a Creationist/IDer who can pose strawmen to try and punch holes in any theory.

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Ironically it was you who erected the strawman. Please answer the question this time, and avoid the man of the straw variety.

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No, the calculations and contents of the paper are no myth. The only myth involved is created by the IDiots

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JonF, you only expose yourself for what you label creationists by blindly defending a completely bogus paper. I read the paper in its entirety, and truly found it to be the worst science I have seen in a long while. Normally this is the kind of stuff you read at T.O., where there is no control. Where were the Royal Society reviewers who let this nonsense through? Playing cricket? Granted even the worst of studies can survive a peer-review, but this one takes the cake. I was not surprised what I found, because I was very skeptical of their conclusion based on common sense knowledge the mathematics problems of evolutionary genetics.Here are just some of the problems, and they are SEVERE:1) The study completely fails to account for genetic deaths! Where are the payments in equation 2 for genetic deaths, such as from deleterious mutations?!!! Essentially they are assuming that each and every random mutation that occurs is beneficial. Wow, a beneficial mutation rate of 100%, and a deleterious rate of 0%. Very impressive!
2) The alleged 80129540 steps are not required to be in any order. So, it doesn’t matter which step occurs, by golly it has a selective advantage!
3) Their claim that they are being generous to assume serial accumulation instead of parallel accumulation is bogus, since each mutation has to essentially pay its own substitution cost (unless the authors think that a mutation can suddenly appear on all the chromosomes of every organism). Gene hitchhiking (linkage disequilibrium) doesn’t help much either because it’s rare.This paper is laughable. To look at it another way, they are claiming that the required mutations are fixating at an average of 220 every generation! Wow! Perhaps some of you remember Haldane’s beneficial substitution rate of 1 per 300 generations? And before you quote Fred Hoyle (who disputed Haldane’s substitution rate), realize that his rate was still no better than 1 per generation. But by golly Nilsson/Pelger get 220 per generation! ROTFL!The paper is a fraud.

They are not modeling for all mutations in the organisms, just those that increase the acuity of the visual system. Therefore there is no such thing as a deleterious mutation in the model, and the overall mutation rate is greater than the mutation rate that is considered in the model. 1829 steps. The number 80129540 does occur in the paper, but it is not
a number of steps. The steps are implicitly required to be in order, since step N+1 canot occur until step N completes. I admit I'm not enough of a geneticist to answer this one. But, given your obvious and total misunderstanding of the paper in all other aspects, I doubt it's a valid criticism.Your claims about the fixation rate are laughable since they are based on your misunderstanding of the number of steps.

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Wow, a beneficial mutation rate of 100%, and a deleterious rate of 0%. Very impressive!

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So, Fred, is their conclusion that an eye would evolve in around 1829 generations? What? It's not??? But they came to the conclusion that there were only 1829 1% modifications needed (of which some can occur in parallel). And, thanks to your wonderful ability to read context (of which I'm sure 3rd graders are envious over), you've come to the conclusion that they were using 100% beneficial mutations. So, my bright friend, how did they end up with a number of years *FAR* more than that?The answer is that they were only assuming a small rate of the genes fixing into the population, using a standard population genetics equation. Yes, they assume that in the long run, bad genes don't fix into the population as a whole. Do *you* debate this? And, when it comes to good genes, they effectively give a 1 in 200 chance.

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the 80129540 steps

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Be mature. You know better. 81029540 is a quantification of the extent of changes; 1829 is the number of steps.

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So, it doesnt matter which step occurs, by golly it has a selective advantage!

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Hey, Fred! If you were working on the design for an airplane and had an entire design team to work on the problems that you're encountering, and you had two choices: A) Have everyone work independently on the same part that is failing - and then as soon as someone comes up with their independent solution, move everyone along to the next failure (again, everyone on the same failure); or B) Have everyone work on different failures. (B) is clearly advantageous. There's absolutely no reason that different organisms can't quite effectively evolve different components at the same time, as long as there is A) sexual reproduction, and B) natural selection.I know you hate to admit it, but they showed they showed that there *is* a continuous path between an eyespot and a fully functional eye, assuming that the types of tissues used in eyes exist. There's not even the slightest question about that - there *IS* a linear path.

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To look at it another way, they are claiming that the required mutations are fixating at an average of 220 every generation!

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Wow, there's your wonderful context reading again! Now you're impressing the 1st graders. *You Read The Number Inverted*. It's one beneficial adaptation fixating out of every 200, not 200 beneficial adaptations in every generation. This is the overall effect of the standard population genetics formula, R=h^sup 2^i*V*m. How can you read something like this *backwards*?Perhaps you should go embarass yourself elsewhere.For those of you just joining us, here are the assumptions underlying Nilsson and Pelger's paper:1) The individual tissues involved can have evolved on their own, as can the nerves; this is only a study of eye morphometry.
2) The initial eye is a small bundle of photoreceptors, surrounded by a small layer of dark pigment, and covered in a thin protective layer.
3) Bad mutations don't fixate into the populations. One in every 200 beneficial mutations fixates.
4) Changes are in 1% steps, linearly.
5) Changes can be stretching, dimpling, growing, shrinking, thickening, thinning, etc.There are legitimate criticisms of the paper out there. They don't weigh in the cost to improvements of the eye (everything in nature bears a cost). They don't list enough of their calculations (although they're fairly simple). They don't pursue alternative routes that could occur at the same time. Etc.The things you brought up, however, did not address any relevant points. You did little more than slander their paper with utmost inaccuracy.------------------
"Illuminant light,
illuminate me."

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Fred: 1) The study completely fails to account for genetic deaths! Where are the payments in equation 2 for genetic deaths, such as from deleterious mutations?!!! Essentially they are assuming that each and every random mutation that occurs is beneficial. Wow, a beneficial mutation rate of 100%, and a deleterious rate of 0%. Very impressive!

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JonF: They are not modeling for all mutations in the organisms, just those that increase the acuity of the visual system. Therefore there is no such thing as a deleterious mutation in the model, and the overall mutation rate is greater than the mutation rate that is considered in the model.

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What? The model is not accounting for genetic deaths, which MUST incur a cost on reproduction. The downward pressure of deleterious mutations is completely removed from their model! Their model is as fallacious as Richard Dawkins Methinks it is a Weasel simulation.

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Fred: The alleged 80129540 steps...

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JonF: 1829 steps. The number 80129540 does occur in the paper, but it is not
a number of steps.

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The 80129540 number is length, which I thought could be equated to steps or more specifically changes. But rereading the paper I stand corrected. What I want to know is the number of substitutions per 1% increment. They conveniently don’t show this (it would expose their illusion). So let’s work backwards. Given 363,992 generations, and Haldane’s substitution rate of 1 per 300 generations yields 1213 allelic substitutions to evolve an eye from a light-sensitive patch! This means that each step is represented by less than 1 substitution! Simply amazing! Well, I guess it isn’t so amazing when you ignore the impact of deleterious mutations, pretending they don’t exist.

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The steps are implicitly required to be in order, since step N+1 canot occur until step N completes.

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No they are not. Label each step S1, S2, etc up to S1829. The steps do not have to occur in order, ie S1, S2, S3 The model allows them to occur S542, S2, S304, The authors support my point by claiming the steps can occur in parallel. They opt to use linear stepping because they want to add to the illusion that they are being pessimistic.I think I am being too kind to merely call the paper an illusion. It’s not clever enough to be an illusion. It’s a fraud, and it should never have passed peer review.

Fred, just because you think that they should have taken an entirely different apporach neither invalditate the paper nor make it a fraud.And that is the sum of your argument.