Design in Bilateral Symmetry and Left-Right Asymmetry Patterns
Mario,
A couple years ago, I made a similar argument about symmetry. It is a very tought matter for any materistic explanation. I argued that for symmetry to exist, then the mechanism whcih codes for one side of an organism would have to have either it's equal but oppostie code for the mirror image features of an organism, or it would have to code for a converter that would convert one side to the other. I was suggesting that if it could be determiend that say the left arm was coded using similar but opposite instructions (if that makes sense) than that which codes for the right arm.. then you have the conundrum of requiring equal mutations for each smallest fraction/segment of symmetry.So, wWhatever portion of the DNA that might code for the righ t elbow, could not directly code for the left elbow..so, an exact inverse function would have to mutate. But evolution is suppose to only happen once, and pleading to convergent evolution for each segment of symmetry is asking to invoke the tooth fairy wayyy too many times - and for every symmetrical organism.
I think if we can find that microtubules and centromeres play critical roles in symmetry, then we will another ground for a shut case agaisnt evolution. Becasue those features are physical constructs of cells that are heritable...and would liekly be empiracally symmetrical at the cellular level !!!
Here's one for you.. what came first.. the hole in your skull or the eye and nerve system that thread through it to the outside? ;) I suppose evolutionist will argue the skull evolved around the optic nerve, but what are the odss that the way it evolved would be in a circle rather than a wedge shape or some other obscure shape tha tmight be just good enough.. why so fine tuned? And if evolution can be argued to fine tune the eye socket so beautifully, and convergent evolution is alwasy happening.. then evolution would be super efficient..but to be super efficient, would mean the universe is suepr fine tuned. I think evolutionists are in a catch 22. Too efficient and it screams mroe-so of ID, not enough efficiency to claim fine tuning and it requires ID to even occur. :)
Indeed. Considering the amount of change required in the genome before acquiring a selectable property, it is very unlikely that organisms went through any successions leading to bilateralism. I note that the genes (dpp/hox) reponsible for the sudden appearance of bilateral symmetry in metazoan morphology show how sudden the change had to have occurred, and also show that they could not acquire any further degradation to the genome.
This way of looking at biological change appears to be more like "saltationism."
I make a similar argument concerning the appearance of larger brains here:
The example you give is also relevant to this issue. The eye, with all of its intricacies requires basal support before it can function anything like it does. If the eye appeared though successions, as has been long suggested, then its basal support must have followed right behind in a nice synchronized fashion.
That is a serious problem for the "randomness" of mutational chages, isn't it?
Mario: "That is a serious problem for the "randomness" of mutational chages, isn't it?"
I suspect so. By the way, I always thought it kind of funny how muscles all have counter opposing muscles. e.g. Biceps vs Triceps. Biceps being counter matched by triceps. Funny :) Why? Because which evovled first? I suppose the evolutionist will have to claim that the tricep evovled first so it could punch the prey out - meanwhile the arm can only dangle to reset itself....and still only later did it evovle the biceps to enable the predator to more conveniently pull the prey to it's mouth. ;)
Same with the eye... whihc of the six muscles that control eye movement came first? Left/Right/Up/Down/ or top or bottom torquiing muscles? I imagine those creatures with only one or two of these must have had some serious lazy eye issues. ;)
Other problems with eye evolution are that tissue parts of the eye brain system form in seperate regions, and grow to join each other into the compleete system. This is nto what I would think evolutionists would rpedict. They should expect, I'd think, expect that all single systems (such as the eye-optic never - brain system) would be a single outgrowth from brain tissue - if anything. How can tissue grow from the brain and meet up with tissue forming the eye-optic nerve without a design plan????????
Read this and see the problem:
http://www.livescience.com/animalworld/060829_embryo_eyes.html
This alone would have to falsified any idea that embryonic development follows evolutionary history of change... among other testiments it poses against evolution theory.
I agree, but I do not see that as problematic. The development of the eye is not the same as the "origin" of the eye. What is interesting to me is the genetic sequence required for the "structural" complexity of the eye. We know that its appearance involves the pax 6 gene (ey locus), but the pax 6 is a control gene that works somewhat like a "switch" for the expression of the entire eye. It is odd, however, that for its expression to be effective, first you must have the genetic sequence responsible for the structure of the eye. Just about every species on the planet make use of the pax 6, yet every eye looks different, so it is logical that the genes responsible for its structure are separate from the genes responsible for its expression. So, unless there is something to “express” (i.e. the structure) then the pax 6 is not needed. How could the pax 6 exist without anticipating the sequence responsible for the structure of the eye?
Another problem can be seen clearly in this article:
Which came first, the brain or the eyes? The article attempts to address this question, but I think is does a really poor job. First of all, it does not address the reason for fully developed eyes in brainless jellyfish, and second, it does not address the fact that recent genetic research shows how the brain is also expressed abruptly through the ASPM gene I mentioned in my “Monkey Brains” piece. If the brain developed quickly, then we must assume it knew how to use the “information” sent by the newly developed eyes. This is another serious problem!
Nice response. Good point on the eye switch. Why a switch, if there's nothing to switch. Does the jellyfish use the Pax6 I wonder? If so, then perhaps more deductions could be made.
Antoher thing about the jelly fish, if the jellyfish does not find the eye useful, then it is by evolutinoary thinking vestigial... but an being vestigial would perhaps imply an organism that use to have brains.. so, apparently evolutionary thinking will have us to consider tha the brain is not that important to survival afterall :P -- funny -- But if the eye of the jellyfish can be found to be not vestigial.. then it had better be useful without a brain... otherwise it falsifies Darwinianism. There may be a catch 22 in this... but I need to hurry tonight - so no deep thinking for me now - Gotta wake up early!
You did not think the development process of the eye was that problematic.. but I think it is mroe problematic than you suggest. One way it can be described, I thkn even by one explanation IO read or clsoe to it - is like so: Imagine people digging from england and tunneling under the English channel to meet with other digger tunneling under the English channel from France.. they meet in the middle and attach phone lines in the middle... of course the lines have to be wired somewhat properly for the system to work. A problem here.. how did the people in England KNOW to meet the peopel from France under the channel.. and how did they meet at the exact spot? It applies to each team of diggers... so goes for the devleopment of the eye. If you do not see this as a serious problem, then what might a just-so story be that an evolutionist would use to expalin the origin of such a develoment process? ie. growing from two unconnected ends to meet in the middle and match many different conductive fibers/the optic nerve for the proper function of the whole system.
You made some good points. I still like the jellyfish.. I think there is more to this creature than first appears to the eyes :-P
I agree that it is a problem, but only in terms of its origin, NOT its development. The reason I say this is that embryonic development can take many different routes to reach the same goal. The problem, as I see it, is in the genetic instructions necessary for it to take any route on the eye's developmental pathway. I do see your point, and it seems as though the system could be irreducibly complex. However, this can only be argued in the context of the system's origin. In other words, the eye develops just fine in embryos, the problem is in how eyes originate without selection playing a role against the anomalies (such as the one you mentioned).
I hope that makes some sense.
Evolutionary theorists sustain that minor genetic variation coupled with natural selection is capable of explaining the diverse number of body plans that exist today. However, it is not clearly understood how evolution is capable of doing so without an exponential increase of genomic information leading to the development of species in the higher taxonomic categories.
Species belonging to the lineage Bilateria make the largest percentage of modern species, and although much conjecture has been made concerning their developmental patterns, it is completely unknown why they seem to appear abruptly in history. To be sure, the genes responsible for the emergence of bilateral symmetry seem to have gone through no trial and error process as one would expect to see within an evolutionary scenario. The fossil record, and indeed, current genetic studies demonstrate bilateralism as an abrupt appearance in metazoan morphology.
As I see it, a greater problem arises when we look at various development genes that pertain to specific body plans. A sequence that corresponds with, say, the development of limbs must also correspond with genes responsible for the limb’s specific cell type, the limb’s structure, limb expression, and limb location.
The same can be said about left-right asymmetry patterns of several organs. Their specific locations are vital to an organism, if it is to survive.
These factors would fall neatly in the hands of design engineering. Bilateralism and left- right asymmetry patterns are essential elements of animal morphology. Current models for developmental pathways do not explain selective advantages of intermediate stages because there are none. From a design perspective, one need only look at the assembly instructions (the genes) and see that bilateralism and left-right asymmetry patterns are essentially good. That is, they are present because they made sense in the designer’s blueprint.
Mario A. Lopez
Ciencia Alternativa
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