From: {$to$}@meden.demon.co.uk   
      
   On 14/03/2025 04:57, MarkE wrote:   
   > On 14/03/2025 12:18 am, Ernest Major wrote:   
   >> On 13/03/2025 11:17, MarkE wrote:   
   >>> On 12/03/2025 9:31 am, Ernest Major wrote:   
   >>>> On 08/03/2025 04:34, MarkE wrote:   
   >>>>> On 7/03/2025 9:29 pm, Ernest Major wrote:   
   >>>>>> On 06/03/2025 00:45, MarkE wrote:   
   >>>>>>> On 5/03/2025 3:31 pm, MarkE wrote:   
   >>>>>>>> Is there a limit to capability of natural selection to refine,   
   >>>>>>>> adapt and create the “appearance of design”? Yes: the mechanism   
   >>>>>>>> itself of “differential reproductive success” has intrinsic   
   >>>>>>>> limitations, whatever it may be able to achieve, and this is   
   >>>>>>>> further constrained by finite time and population sizes.   
   >>>>>>>>   
   >>>>>>>   
   >>>>>>>    
   >>>>>>>   
   >>>>>>> Martin, let's stay on topic. Would you agree that there are   
   >>>>>>> limits to NS as described, which lead to an upper limit to   
   >>>>>>> functional complexity in living things?   
   >>>>>>>   
   >>>>>>> How these limits might be determined is a separate issue, but the   
   >>>>>>> first step is establishing this premise.   
   >>>>>>>   
   >>>>>>   
   >>>>>> First, natural selection is not the only evolutionary process.   
   >>>>>> Even if one evolutionary process is not capable of achieving   
   >>>>>> something that doesn't mean that evolutionary processes in toto   
   >>>>>> are not capable of achieving that.   
   >>>>>   
   >>>>> Natural selection is the *only* naturalistic means capable of   
   >>>>> increasing functional complexity   
   >>>>   
   >>>> Creationists have been known to argue that natural selection doesn't   
   >>>> create anything; it merely selects what's already present. As an   
   >>>> argument against evolution that's worthless; but as an observation   
   >>>> it's true enough. Each step in functionality complexity originates   
   >>>> from mutation, or recombination, or gene flow, and is subsequently   
   >>>> fixed or not by natural selection or genetic drift.   
   >>>>   
   >>>> For example Ron Okimoto (I think) recently mentioned that one   
   >>>> flagellar gene is a truncated version of another, and results in the   
   >>>> assembly of a tapered flagellum rather than cylindrical one. I can   
   >>>> imagine that the tapered flagellum is advantageous, and was fixed by   
   >>>> selection. It might be that the gene was duplicated and fixed by   
   >>>> drift before a truncation mutation occurred, but as selection   
   >>>> against excess DNA is effective in bacteria I suspect that it   
   >>>> originated as a partial duplication of the gene, which was then   
   >>>> selected. But note that the initial increase in complexity was   
   >>>> caused by the mutation. Natural selection fixes this in a   
   >>>> population, and as you have mentioned acts as a ratchet allowing   
   >>>> changes to accumulate.   
   >>>>   
   >>>> But you are assuming increases in functional complexity are   
   >>>> adaptive. They could be neutral or slightly deleterious and fixed by   
   >>>> genetic drift. I don't accept without question your   
   >>>> panadaptationist/ panfunctionalist premise.   
   >>>>   
   >>>> Passing over the problems with defining an objective criterion for   
   >>>> irreducibly complex systems, there are at least three classes of   
   >>>> evolutionary paths to this. I think that coadaptation is the   
   >>>> predominant one. This goes from non-interaction to facultative   
   >>>> interaction to obligate interaction. Both steps could be fixed by   
   >>>> either natural selection or genetic drift.   
   >>>>   
   >>>>> and genetic information.   
   >>>>   
   >>>> Increases in functional complexity and genetic information are not   
   >>>> the same thing. If you use a Shannon or Kolmgorov measure natural   
   >>>> selection tends to reduce, not increase, information in a gene pool.   
   >>>>>   
   >>>>> All other factors have only a shuffling/randomising effect. In   
   >>>>> every case, NS is required to pick from the many resulting   
   >>>>> permutations the rare chance improvements.   
   >>>>>   
   >>>>> Without the action of NS, all biological systems are degrading over   
   >>>>> time.   
   >>>>>   
   >>>>>>   
   >>>>>> Second, you've changed the question. Evolutionary processes have   
   >>>>>> limitations, but those limitations need not be on the degree of   
   >>>>>> functional complexity achievable. Evolution cannot produce living   
   >>>>>> organisms that can't exist in the universe. (You could quibble   
   >>>>>> about lethal mutations, recessives, etc., but I hope you can   
   >>>>>> perceive the intent of my phrasing; for example, I very much doubt   
   >>>>>> that evolution could result in an organism with a volume measured   
   >>>>>> in cubic light years.)   
   >>>>>>   
   >>>>>> Applying this to functional complexity, physical limits on how big   
   >>>>>> an organism can be, and how small details can be, do pose a limit   
   >>>>>> on how much functional complexity can be packed into an organism.   
   >>>>>> But such a limit doesn't help you - humans are clearly capable of   
   >>>>>> existing in this universe, so aren't precluded by that limit. You   
   >>>>>> need a process limitation, not a physical limitation; I don't find   
   >>>>>> it obvious that there is a process limitation that applies here.   
   >>>>>>   
      
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