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  Topic: Nelson Alonso and front loading< Next Oldest | Next Newest >  

Posts: 36
Joined: May 2002

(Permalink) Posted: Jan. 12 2003,20:28   

Dear Nelson.

It seems clear to me that you are ignoring the details provided by me about possible pathways for evolution.

If you claim that front loading explains Pecten then you accept that evolution can generate the eye as found in Pecten unless you are not talking really about front loading but intervention.

Perhaps you can first share with us your front loading hypothesis wrt for instance Pecten and the Lobster? In fact you suggested that Pax-6 gene 'supports front loading' but if that is the case your argument seems to be that given the existence of Pax-6 at an instant t=t_0 you expect evolution to lead to the large variety of eye 'designs' as found in nature. Is that correct or are you backtracking your claims that let's say every species/family/genus/ or at whatever level was 'front loaded' independently at different instances in time/space?

I doubt that one can make a logically consistent claim of front loading that is not contradicted by the data other than through the Pax-6 gene. But Pax-6 seems to be going back in time quite some distance, long before the family Pectinidae arose.
To me it seems that you are not arguing for front loading but rather intervention since your objections seem to be terribly ad hoc and seem to refuse to recognize natural pathways to these structures. If that is the case then you cannot be arguing for front loading since teleological front loading is defined to be at t=t_0 the necessary information was inserted so that at a given time t1, with t1>t0, a certain feature arises in a certain family/species. Non teleological front loading would be that at a certain instance t=t_0 an initial state exists and we can trace back to such an initial state showing how the various eye 'designs' all seem to trace back to ancestral forms.

As far as the references to Korthof et al, they are meant to help the interested reader understand many of the problems found in Denton's work.

It seems evident to me that Nelson has not familiarized himself with the papers he quotes but rather that he is relying on second hand information which may or may not be relevant or even accurate. As I have shown, Dakin's 1908 statements are explained in more detail in 1967 and onwards where it was shown that the Pecten eye is very likely an evolutionary  continuation of the single retina eye with the addition of a reflecting layer. The transition is even better to understand from a selective evolutionary viewpoint when realizing the advantage of these changes namely the ability to see both in and outside water. Combine this with the fact that the Pecten resides in a tidal affected area and thus may be exposed to both water and air and one realizes the selective advantage of the Pecten eye. Thus we have found the answer to Dakin's uncertainties. Nelson complains that I do not provide sufficient detail how natural selection and mutation built these eyes but if Nelson were to argue for front loading he would have no choice but to accept that natural forces can lead to the Pecten eye or Nelson should drop his claims about Pecten and front loading. Surely our ignorance of certain details should not be taken as evidence for front loading. In fact although we have not yet obtained all the necessary evidence a plausible pathway has been provided. Nelson may be complaining about 'sufficient details' but the amount of detail so far already exceeds any alternative hypothesis. And since Nelson seems to want to argue front loading he also by default has to accept some time period in which evolutionary processes shaped the eye of Pecten to what it is right now.

Nelson then raises the spectre of Spondylus, which attaches to rocks as if this forms a problem. Until Nelson can show us from the original research papers what the eye of the Spondylus looks like as compared to Pecten we have no real way to discuss this. Secondly until Nelson shows that there is actually a problem explaining the evolution of the eye in Spondylus and Pecten, we merely can speculate about what Nelson's 'argument may be'. Since Nelson seems to accept the evolutionary history of Pecten and Spondylus one may wonder why he seems to oppose that evolutionary processes led to the eye 'designs' since he does seem to accept front loading and common descent. Perhaps Nelson believes that another mechanism than evolutionary mechanisms played a role? He mentions front loading but as I have shown that merely states that at a given stage in time t=t_0 information was injected into the genome to allow Pecten and Spondylus to form their respective eyes. The fact the pectinacea were ancestral to Spondylidae surely supports the evolutionary pathway. So it is not clear to me how Nelson suggests front loading could have helped Pecten and Spondylidae. In fact, if Nelson is correct about the location of the Spondylus and its eyes (so far the data seem to be vague on either aspect) then Nelson may have to explain why a front loader would lead to a system which is now defunct namely the ability to see in air.

Nelson then confuses the issue of front loading and intervention even further when he states
If these biological features were poised to evolve into greater complexity through an intelligent agent then it wouldn't have been as difficult as a blind force tinkering with such a complex system.

Is Nelson suggesting that evolution is guided through an intelligent agent. Then he should not be arguing for front loading but instead for intervention.

Nelson still seems to be unwilling to deal with the available evidence which includes intermediate stages for the varieties of simple and compound eyes. Perhaps Nelson wants to argue that the details are not sufficient but that's just a matter of time for science to find all the common genes and variations that have led to the variety of eyes as found in nature. So far the evidence strongly suggests both evolutionary mechanisms and at least for many basic components a common ancestor.

If Nelson had taken the time to look at the pictures then he would have noticed how these portray the variety of intermediate paths likely to have been taken in the evolution of the various eye forms.

Nelson still repeats his so far unsupported assertion that
Again, none of this shows how blind natural forces would, nor does it even explain why, natural selection would guide the organism down the difficult road of refraction to reflection in my particular examples

1. Could Nelson show that the road of refraction to reflection is difficult
2. Could Nelson show that the road of refraction to reflection is even relevant for the lobster?

Nelson confuses the situation even further by claiming that


However, what I would expect from a Front-Loading persepective is that every step of the way was every bit more complex then the last, however, through the help of pre-positioned elements the evolution of these eyes was directed through intelligent agency.

So is it front loading or is it intervention? If it is front loading then we have the situation that at a certain time the information needed for evolution to play out was injected into the genome of a common ancestor and that from this common ancestor all the descendants arose with the large variety of eyes. Ignoring for the moment the grasping at straw nature of such a front loading scenario which would have to play out through an inherent chaotic and thus unpredictable system and interactions to eventually lead to the eye of the Pecten. Nelson presents no more evidence than that a some moment the basic building blocks were present that eventually would allow the Pecten or any other organism to evolve an eye design. No effort is made by Nelson to show that the eyes of the lobster are optimal for the functioning of the lobster. In fact Nelson merely argues that for the lobster eye, the eyes are perfect squares that are fine-tuned for the vision of lobster. No further information is presented to support this case. And if Nelson wants to consider fine-tuning and continue to argue for front loading then Nelson de facto has accepted the fine tuning power of evolutionary processes.

Given the contradictory stance of Nelson on the issue of front loading I would encourage Nelson to address the following issues.

1. Explain the hypothesis of front loading as it applies to Pecten.
2. If Nelson accepts front loading then does Nelson accepts that natural processes are responsible for the shaping of the eyes of Pecten? In absence of such an acceptance, Nelson cannot be talking about front loading here.
3. Can Nelson explain in detail the similarities and differences between Pecten and Spondylus and can Nelson provide us with the arguments proposed by Dakin? Do the findings apply to the whole family of Spondylus or just some particular species? After all the various species of Spondylus do seem to occupy a large variety of ecological niches
4. Can Nelson show that the lobster eyes are perfect squares or is Nelson using stylized drawings to reach these conclusions?

Perhaps Nelson may want to explain why the squares in the following picture are all but perfect?

Perhaps Nelson was confused by the resulting drawings?

Perhaps Nelson can also appreciate what perfect squares really would look like?


Posts: 36
Joined: May 2002

(Permalink) Posted: Jan. 13 2003,23:14   

Dear Nelson,

May I suggest that when you quote from Answers in Genesis that you at least provide for the correct reference? And it would be helpful that you would indicate that you are quoting from a secondary source.


The eye of a lobster (and some other 10-legged crustaceans1 including shrimps and prawns) shows a remarkable geometry not found elsewhere in nature—it has tiny facets that are perfectly square, so it ‘looks like perfect graph paper.’2

2. Hartline, B.K., Lobster-eye x-ray telescope envisioned, Science 207(4426):47, 4 January 1980.


And while at smaller resolution indeed this may seem to be perfect, reality shows that at high magnification they are hardly that perfect.

Another example of these 'perfect squares' in prawn shrimps

I would like to point out that my main objection is to Nelson's claims that no evolutionary pathways or selective advantages have been shown for the evolution of eyes, particularly in lobsters and Pecten. By relying on second hand resources which have been shown to be of doubtful accuracy in many other areas, Nelson has been furthering an argument for which he does not seem to have any first hand information. And yet he is willing to make claims that would go beyond what would be supportable without any knowledge of first hand sources. This has led Nelson to make such assertions as 'perfect squares' when in fact the photos show that they are hardly such. Other mishaps have been documented elsewhere and in the rest of this posting.

The moral of the story is that if one wants to argue that t is the failure of natural selection and RM alone to account for these eyes that opens the door to front-loading. one should be familiar with the actual evidence and not some second hand resource.

Nelson still seems to be unable to grasp the simple fact that the observation that Pecten needs to see in and outside the water may explain the selective advantage of an eye that can see in both environments. The difference between the Pecten and its precursors need not be that large when one realizes the likely pathways.


As noted in Chapter 1, the case of Pecten is fascinating. It has evolved an eye with two separate retinas placed
next to each other but separated from the tapetum and other elements at the posterior of the optical orb. The
tapetum has become a reflective mirror in a catadioptric optical system consisting of the objective group and the
tapetum. When the eye is immersed in sea water, the cornea is ineffective but the crystalline lens and the tapetum
combine to form a catadioptric optical system bringing light to focus on one of the two retinas. When the eye is
not immersed in sea water, the cornea of the objective group is effective and the cornea and crystalline lens operate
as a dioptric optical system with the other retina. This provides an animal living in an estuary with focused vision
under both aquatic and terrestrial conditions.


First of all the reflector. It should be noticed that


The tapetum sheet can evolve to form a variety of functions depending on the animal. It is generally a passive
layer. Normally, it can aid in the absorption of stray light that has passed through the retina. In some cases, it
consists of small groups of cells that act as a retro-reflector to direct light back through the retina. As seen in the
case of the mollusc, Pecten, the cells can also be used to form an optically coherent sheet of cells that form a
reflecting optical element in a catadioptric lens system.


Now the retina


The individual photoreceptors are similar in structure to those of Arthropoda, i.e., the chromophoric material is
found in rods exuded from the sides of the photoreceptor cells. .... Whereas the rhabdom of Arthropoda
exhibits a circular symmetry with respect to the centerline of the assembly, this is much less evident or
nonexistent in Mollusca. The limited data available indicates an orthogonal grouping of photoreceptor cells
to achieve a higher sensitivity to the polarization of the incident light.



It is the failure of natural selection and RM alone to account for these eyes that opens the door to front-loading.

In fact you have failed to show that RM&NS are a failure to account for these eyes so there goes your justification for front loading but you seem to still be unable to describe to us what front loading really is, other than not RM&NS..
Describe your front loading scenario in some detail please. And explain what mechanisms you have in mind that played out for times > t_0 (the time of front loading). I would encourage you to check out some of the works on Intelligent Design that would allow you to familiarize yourself with the concepts and their strengths and weaknesses.


3. You say: " Spondylus Until Nelson can show us from the original research papers what the eye of the Spondylus looks like as compared to Pecten we have no real way to discuss this."

You did this yourself:

In the Spondylus and Pectinidae, the eyes are quite well developed consisting of a cornea, lens and retina.

That suggests to me that Nelson is not familiar with the primary sources that describe the eyes of Pecten and Spondylus. In fact as far as I have been able to tell Spondylus eyes are not like Pecten eyes at all.

For instance from Ibid:

use of two separate optical forms within the available physical envelope in Pecten, including introduction of an
entirely new optical form to animal physiology--a catadioptric lens system.

Pecten seems to be unique in this aspect. Perhaps Nelson can present us in some more detail Spondylus? Which species of Spondylus btw is Nelson refering to?


Anyway, my discussion of front-loading and eye development center around pax-6. Pax-6 has remained more or less the same in most branches of life. In every animal examined that has eyes this gene proves to be involed in eye development. Moreover, it is necessary for function. In both Mice and flies pax6 mutations severely affect development of eyes. Drosophila has two closely related pax6 genes, eyeless (ey) and twin of eyeless (toy). Expresssion of either of these genes in antennal, leg and wing imaginal discs in drosophila causes well formed ectopic eyes. In xenopus embryos ectopic injection of pax6 into blastomeres causes ectopic eye-like structures. So not only is Pax6 required for eye formation, it is also the author of eye development. Pax-6 genes control both upstream and terminal functions in the gene network for eye development. Since pax-6 genes also exist in primitive organisms like sponges, a prediction of FL (Mike or Warren can correct me if I'm wrong) would be that it plays a non-essential role in these organisms.

So far so good so we have evidence that evolution shaped the expression of the Pax-6 gene as well as many other hox genes. But how does this show evidence of front loading? That essential genes have changed little over time but have been quite able to lead to different evolutionary shapes shows how a simple variation on the timing of embryological development may have a significant impact on the resulting form. But as with Mike Gene, Nelson is now painting an arrow around the bullseye by arguing that evidence of common descent is suddenly evidence of 'front loading'. Well we all agree that at t=t_0 pax-6 gene existed as an initial condition and how RM&NS played a role in shaping life there after. If Nelson wants to argue front loading then he surely has to accept the role of natural forces shaping evolution for t>t_0 or he is arguing for intervention rather than front loading. But while evolution can explain in a non ad hoc manner the evidence, Nelson seems to want to argue, without much evidence, that this front loading or initial condition required intelligent design. Yet in the actual discussion Nelson seems to be wavering between front loading and intervention and so far has been unable to provide us with the necessary details.

Nelson claims that the quote came from Denton but according to "Design in Nature by HARUN YAHYA" the reference in Denton is:


The eye of a lobster shows a remarkable geometry not found elsewhere in nature - it has tiny facets that are perfectly square, so it "looks like perfect graph paper."2

2. J.R.P. Angel, “Lobster Eyes as X-ray Telescopes”, Astrophysical Journal, 1979, 233:364-373, cited in Michael
Denton, Nature’s Destiny, The Free Press, 1998, p. 354

The reason I thought it was AIG was because your reference

Land, M.F., Animal eyes with mirror optics, Scientific American 239(6):88–99 1978 matches their
Land, M.F., Animal eyes with mirror optics, Scientific American 239(6):88–99, December 1978 remarkably well.

In either case your reference seems to be erroneous as far as I can tell. This can be avoided by actually reading the references from which one quotes. In fact relying on Denton is never a good policy, which is why I included some references to reviews which show some serious shortcomings in his interpretation of scientific work. The author may have refered to them as looking like perfect squares but I have shown they are hardly such, especially when realizing the relevant optical wavelengths.


Posts: 36
Joined: May 2002

(Permalink) Posted: Jan. 15 2003,12:30   

Archived from ISCID:


First of all, I would like to apologize to you if my reference to the AIG website caused you any distress. My comments led to me being banned from posting [on ISCID] for one day because among others,according to the email from one of the [ISCID] moderators, may have been interpreted as an attempt to 'smear[ed] [your] face in the mud of creationism'. If that's the case then I would like to point out that I had no intention to smear your face in such mud and will openly apologize if such impression was raised by my posting. Rather I wanted to point out that your quote of primary research was erroneous. It was my mistake that I concluded that you had quoted from AIG rather than from Denton.

I will from now on strengthen my attempt to be more patient in my replies in order to encourage an open discussion of ideas on this forum. I thoroughly enjoy our discussions here and I hope that others feel similarly.

Per [ISCID] moderator's suggestion I will also not provide any more links to the archive of my postings.

I hope that these steps can be helpful in generating an atmosphere in which we can discuss ID ideas in a constructive manner.

  2 replies since Jan. 12 2003,20:28 < Next Oldest | Next Newest >  


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