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| Mike Gene - Error Correction Runs Deep | Pages: 1 - 2 - 3 - 4 - 5 |
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by «¥» Plump-DJ® «¥» (Member
# 402) on 26. September 2002, 13:36: And I wonder how Evolution, driven by that immediacy for survival and advantage could ever hope to "come up" with as it were something that mirrors the parity bit used in data communications. Was there a 'non-parity-bit' stage in the evolution of life or maybe even a "half-parity-bit" stage? I personaly can't see how something like this could arise, step by pre-biotic Darwinian step. Posted by warren_bergerson (Member # 262) on 27. September 2002, 11:17: Mike, Quote: In trying to understand the origin of the parity-code, Mac Donaill writes, "The critical question is whether the parity-code structure is accidental, or shaped by selection through evolutionary advantage." It is understandable that non-teleologists would frame this question in a binary fashion - chance or selection. But teleologists have a third option. That is, while they can agree with the selectionists that chance is not a good explanation, they propose an intelligent designer rather than the blind watchmaker. In addition to looking at the ‘source’ or cause of error correction, it is also interesting to look at the result or effect of error correction on the processes of evolutionary change. Error correction is an example of what I call ‘selection acting directly on genes’. Many potential alleles or mutations are in effect selected out before they have any opportunity to produce any phenotype effects. The simplest interpretation of error correction, is that it has the effect of reducing mutation rates. In the extreme case, completely efficient error correction would eliminate the effect of mutation. As should be obvious, with no source of diversity, evolutionary change could not occur. Even incomplete or partial error correction can significantly slow down both mutation rates, and reduce the number of different ‘random mutations’ which are generated. If one assumes, as suggested that RM&NS, 1)that genetic change is the result of the interaction of natural or phenotype selection, and ‘net mutation rates’, and 2)that all genotype selection is error correction, then using techniques discussed in ‘selection acting directly on genes’, I believe, you can measure/estimate the speed, cost in lives, and the complexity/volume of genetic change produced by a genome. I believe, (I haven’t actually done the calculations) that, adjusted for error correction and genetic selection, a biological systems using ‘Darwinian evolutionary processes’ would have a very limited, but measurable capacity to evolve. Parity codes and other error correction mechanisms are powerful brakes applied to evolutionary change processes. Whether these brakes arose by chance, selection or external intervention, the existence of these brakes suggests that there must also exist some as yet unidentified gas pedal. Posted by Frances (Member # 169) on 27. September 2002, 12:42: If as you seem to suggest error correction is part of GSH and if error correction reduces evolution then it seems that it's not Darwinian mechanisms but GSH that suffers from problems explaining the facts of evolution. Btw intelligent design is not a hypothesis limited to ID, in fact it could equally well be proposed and is sometimes proposed by scientists. Thus ID perse is nothing new in science and in limited form ID can be quite succesful in some sciences. Things get more complicated if regularity hypotheses need to be considered in addition to chance. Posted by Mike Gene (Member # 149) on 02. October 2002, 21:43: Hi DJ, I do agree that the deeper you go, the stronger the impression of design or teleology seems to get. This is the primary thing that fuels my ID hunches. For it didn't have to turn out this way. On the other hand, maybe it did. Suffice it to say that non-teleologists did not anticipate such Deep Teleology. Check out how Science reports on this new finding - "The Genome Chose Its Alphabet With Care." The article quotes another scientist:
The genetic code is not the "frozen accident" non-teleologists originally thought it to be. It was "chosen." Now, the use of A,G,C,and T is apparently not the "accident" non-teleologists originally thought it to be. It too was "chosen." Posted
by yersinia (Member # 324) on 02. October 2002, 21:58:
But then again... quote: Nat Rev Mol Cell Biol 2001 Feb;2(2):147-51 Confounded cytosine! Tinkering and the evolution of DNA. Poole A, Penny D, Sjoberg BM. Institute of Molecular BioSciences, PO Box 11222, Massey University, Palmerston North, New Zealand. a.m.poole@massey.ac.nz Early in the history of DNA, thymine replaced uracil, thus solving
a short-term problem for storing genetic information--mutation of cytosine
to uracil through deamination. Any engineer would have replaced cytosine,
but evolution is a tinkerer not an engineer. By keeping cytosine and
replacing uracil the problem was never eliminated, returning once again
with the advent of DNA methylation. Posted by Mike Gene (Member # 149) on 04. October 2002, 23:04: Posted by Janitor@MIT (Member # 125) on 08. October 2002, 10:49: I noticed that the IDers are fretting over a research program: One of the outstanding problems, if not the most outstanding problem, in evolutionary biology is decoding the code. Until we’ve done that any confident statements about the process of evolution are going to be ridiculously premature. But this is going to be a difficult task, as any sufficiently advanced communications and control technology will appear to be “magic.” (LOL) The IDers should have a “conceptual” advantage here, not being possessed of the “cargo cult” view of the design of life that prevails in evolutionary biology. (Sorry, Mr. Moderator, that was a shot, I know.) I think that even if their research program focused solely on the code they could be productively occupied for quite some time, with the very real possibility of making some fundamental contributions to biology. Posted
by Mike Gene (Member # 149) on 09. October 2002, 06:58: I agree (although fretting over a research program doesn't really apply to me). As it stands today, evolution is still largely a black box. Take the well-documented reptile-to-mammal transition. We may know that it happened, but we have very little understanding of how it happened. The Darwinian "mechanism" offers only a vague heuristic perspective - something happened in some environment to increase the relative fitness of some vague,pre-mammal-like organisms. While such happenings may have been involved in such evolution, there is no reason to think they alone were the driving force. What were the molecular changes driving this evolution? How did they actually come about? Deeply embedded in the non-teleological approach is an appeal to things that "just happen." In the case of such evolutionary explanations, we ultimately pose mutations that "just happen" in situations the organisms just happen to be. What should be encouraging to teleologists is the way these "just happen" explanations are being abandoned. The genetic code as a "frozen accident?" Nope, there is a design behind it. The choice of A,G,C, and T as an accident? Nope, there is a design behind it. The use of a particular nitrogenous base (cytosine) prone to deamination that just happens to spawn the other pyrimidine member of the parity code (thymine/uracil) is an accident overlooked by a myopic tinkerer? Hmmm. Sounds like a juicy TeleoLogic essay in the making. Posted by Janitor@MIT (Member # 125) on 10. October 2002, 13:29: Posted by Mike Gene (Member # 149) on 12. November 2002, 00:33: 1. Would an engineer really preclude cytosine as Nic's citation asserts?
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