Posted on 06/15/2003 10:36:08 AM PDT by Alamo-Girl
After reading it closely, that is what Schroeder is saying, though he does it in a circuitous fashion. In an evolutionary system, one would expect there to be a conservation of basic bootstrap systems (its practically required) at some fundamental level. Even though the particular protein system found in animals is generally the same, the number of independent photo-reactive expressions (e.g. "eyes") is actually quite large (40+ known independent systems IIRC), and the number of photo-active expressions is too large to count. Photo-activity is a very active part of biological systems and evolves rapidly, mostly because photo-activity in chemistry is so common. There are also a number of other independent unrelated systems that have the same function in non-animals, but it seems like those were ignored for the sake of painting a pretty picture. It is roughly analogous to saying that because all cars are made of steel, all cars are the same. The raw material says almost nothing about the nature of the useful form, and it ignores the fact that while most cars are made of steel, there are also some that are not.
Since photo-receptivity is a common property in chemistry, there is nothing intrinsically special about the system protein system in question. If anything, conservation of the protein framework that animal photoreceptive systems are bootstrapped off of (in a pretty indirect fashion) suggests an evolutionary history, since there is no good design reason to have that particular framework in all animals unless it is a trait that has been conserved through evolution. The protein framework was not particularly optimal, but it was highly adaptable which is a trait only of value in an evolutionary schema.
From where I'm sitting, it looks like a perfect argument for evolution, where adaptability of a useful protein system was selected for rather than optimality of function because it made the system survivable. If I'm building a race car, I don't borrow parts off a pickup truck, but I probably could if I really had to. That's kind of where the eye biochemistry thing is at. There is evidence of many other eye type systems in biology, but most of the ones that we find today are those best suited for conservation in an evolutionary system rather than ones that would work best for a particular species.
Schroeder almost boils down to an argument from incredulity. I'm mostly extremely dubious of his argument because it carefully omits certain facts and avoids properly accurate representations that would damage the construction of his position. That is the behavior of a snake oil salesman, not a true scientist.
All this frame-shifting and name-associating is too much for me!
What you are saying is not strictly true, but the point is minor enough that it doesn't really change things one way or the other.
More importantly, DNA doesn't "do" anything, merely providing a template. Building proteins off that template is an extremely biased system, and we expend a fair portion of our supercomputing power today figuring out what protein conformations are probable under certain circumstances and which aren't. The combinatorial space IS astronomically huge, and sifting through the vast quantities of chemically improbable combinations to find the small number of highly probable combinations is not trivial and won't be for a long time, running into what is essentially an expression of the Halting Problem of computational theory.
This is like saying, organisms don't "do" anything, they just propagate.
In a sense, this is essentially true depending on how you look at it.
My point was that most of the phase space filtering doesn't occur in the DNA itself, so the distibution there doesn't really matter. It is largely the substrate.
The significance of this statement must not be lost. We are being asked to reexamine the idea that evolution is a free agent. The convergence, the similarity of these genes, is so great that it could not, it did not, happen by chance random reactions.
From where I'm sitting, it looks like a perfect argument for evolution, where adaptability of a useful protein system was selected for rather than optimality of function because it made the system survivable.
None of them, including Schroeder, is hostile to evolution. But that doesn't mean these scientists are willing to accept descriptions without explanation. That is the point of this exercise.
The reaction of attacking their good name does not reflect favorably on the evolutionists here.
The most characteristic element in this situation seemed to me the incessant stream of confirmations, of observations which "verified" the theories in question; and this point was constantly emphasize by their adherents. A Marxist could not open a newspaper without finding on every page confirming evidence for his interpretation of history; not only in the news, but also in its presentation — which revealed the class bias of the paper — and especially of course what the paper did not say. The Freudian analysts emphasized that their theories were constantly verified by their "clinical observations." …
The object of the essay was to look at what the mathematicians and physicists are bringing to the table with regard to evolution. Here are the sources and the areas they question, in reverse order:
Thank you!
... ;-}
Recently, i've waded into the effect of each of our perspective views on things, (e.g. - reality is something we all percieve through the senses and we need to be very humble and careful about what we define as 'real' or not), and also some of the ideas of the famous quantum physicist David Bohm (excellent article by David Pratt) who turned towards the east for insight into this reality we live in...
Where do you get this information from? Pax genes are important developmental transcription factors. These factors regulate the expression of other genes. Pax-6 is functional in early developmental pathways even in organisms that don't have eyes.
Is it possible that you are referring to an ancient duplication event that led to the temporary inactivity of one of the genes which was later coopted? We know of at least 10 PAX genes. The obvious scenario is gene-duplication followed by mutation. A small mutation in a transcription factor leads to large-scale changes down-stream.
I am a Platonist - more like Penrose than Hawking. For instance, I perceive that geometry exists in reality and the mathematician comes along and discovers it, e.g. pi, Schwarzschild Geometry, Riemannian Geometry and so on.
I suppose I can be accused of oversimplifying but this seeming "chicken-and-egg problem" as to which came first, form or reality, to me boils down to that the discovery of mathematical beauty, again and again and again, is found to extremely fine tolerances to be a description of reality as it is, again and again and again. If the form, mathematics, was not first, then it is at least foundational to reality and in that sense integral and indispensable. I think this is undeniable. I would never suggest that mathematical structure IS reality but I would say that God is a heck of a mathematician. Or if not God, where did all the intricate mathematical structure come from and why does it relate so directly to reality? Beyond what we know of our reality and acknowledging their role in our reality, do imaginary numbers play some intimate, direct role in some strange, undiscovered reality?
And this dichotomy between the pictures of reality presented by quantum mechanics and classical physics, the "phase collapse problem" I suppose I could call it, is a chasm as immensely huge as the Grand Canyon, plenty of room for consciousness, free will and anything else you might want to throw in, including the kitchen sink. It is a true unresolved paradox, yet it's been shown to be quite real.
We're "not there yet" in my view by any stretch. I'm still reading and digesting your fine, fine essay. And all this is FWIW and "My 2 cents" ...
Indeed, our concept of "reality" has a great deal to do with our attitude about everything. I look forward to any further comments you may have!
Amazing to me is that the gene is conserved across phyla. Between human and mouse, it is 100% identical and between human and drosophilia 94%.
We also know that eyes form whereever they are expressed, i.e. ectopic (eyes on a wing, etc.) Mouse Pax-6 in drosophilia leads to fully formed ectopic eyes – and vice versa!
The assertion was that the Pax-6 in the common ancestor was a factor in survival. I challenged that assertion per se because at that level, the organism had no eyes – thus nothing manifest physically as a factor for survival. The secondary argument was that the Pax-6 gene made the organism more adaptable. But that could be said of any Pax, as you noted – thus I didn’t address it.
No, the Pax-6 gene is seperate from the genes that code for the eye. DNA evidence (as I posted above) indicate that those genes arose independently.
Amazing to me is that the gene is conserved across phyla. Between human and mouse, it is 100% identical and between human and drosophilia 94%.
It makes a lot of sense when you understand the phylogenetic relationship between organisms. Humans and mouse are much more closely related than humans and flies.
We also know that eyes form whereever they are expressed, i.e. ectopic (eyes on a wing, etc.) Mouse Pax-6 in drosophilia leads to fully formed ectopic eyes – and vice versa!
Yes. The genes for eye development are present in all tissues and Pax-6 (highly conserved) is able to activate the developmental pathway in several other tissues.
The assertion was that the Pax-6 in the common ancestor was a factor in survival. I challenged that assertion per se because at that level, the organism had no eyes – thus nothing manifest physically as a factor for survival.
I guess it didn't occur to you that transcription factors can be used for regulation of other genes. Recruitment of genes for different purposes is a common theme in evolution.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.