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On 14/03/2025 12:18 am, Ernest Major wrote:You were being invited to address your vacillation about whether you claim that there is an upper limit to the amount of functional complexity that evolution can generate.On 13/03/2025 11:17, MarkE wrote:To recap different contributing factors to an upper limit in functional complexity in living things in relation to natural selection: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.>
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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?
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How these limits might be determined is a separate issue, but the first step is establishing this premise.
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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.
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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.
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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.
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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.
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Without the action of NS, all biological systems are degrading over time.
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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.)
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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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You say that the first step is establishing the premise. That is your job.
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That there are things that evolution cannot achieve (a classic example is the wheel, though even that is not unimaginable) doesn't not mean that evolution cannot achieve things that already exist; one of the reasons that ID is not science is it's lack of interest in accounting for the voluminous evidence that evolution has achieved the current biosphere.
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The limits of NS are not simply due to physically possible organisms. It's much tighter constraint. The mechanism of "differential reproductive success" is a blunt instrument, rightly described as explaining the survival but not arrival of the fittest.
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To elaborate my hypotheses (not proofs):
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1. NS, along with any other naturalistic mechanisms, do not have the logical capacity to fully traverse the solution space, regardless of time available. Some (many) areas of the fitness landscape will be islands, local maxima, inaccessible via gradualistic pathways (e.g. monotonically increasing fitness functions). These are however accessible to intelligent design.
You are moving the target again. It is not legitimate to take the probably truism that evolution cannot reach all targets, and use that to argue that are limits to the degree of complexity that evolution can generate.
I'm not claiming a limit the degree of complexity that evolution can generate, but rather the extent of of the solution space.
"Would you agree that there are limits to NS as described, which lead to an upper limit to functional complexity in living things?" - MarkE, 5th March 2025. (Quoted by MarkE on the 13th March 2025 - see above.)
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1. Fitness landscapeFitness landscapes are often illustrated as two-dimensional surfaces. This makes it easier to visualise them, but also makes it easy to imagine isolated peaks of fitness. Real fitness landscapes have much higher dimensions and also shift with time (changing environments). The mathematics may well be beyond me, but at first sight it would seem that the more dimensions there are the greater likelihood of there being an upwards path in at least one dimension. And then there's the effects of changing environment, making the likelihood of there being an upward path in a least one dimension at some time.
If the fitness landscape has unreachable islands (local maxima sparsely distributed in a plain), then if some of these represent "solutions" of greater functional complexity than those in local maxima accessible to NS, this implies an upper limit, lower than that of all physically possible organisms.
This is conditional, as indicated by the two 'if' statements it contains.
No such constraint applies to an intelligent designer with access to the entire solution space.Different constraints apply to an intelligent designer with access to the entire solution space. Evolution has no problem in identifying peaks, but may have problems finding paths towards them. An intelligent designer may less constrained by paths, but has the problem of telling whether a particular design sits on a peak.
2. Time availableClaims that evolution can achieve X, and claims that there hasn't been enough time for evolution to achieve X, are not the same thing. I wish you'd stop conflating them.
If the time/material resources of the universe allow exploration and discovery of only a fraction of even the accessible solutions, this places another upper limit on the functional complexity that could be realised.
Again, this constraint does not apply to an intelligent designer.
3. The intrinsic capacity of NSThat doesn't seem to be a 3rd claim.
The mechanism of "differential reproductive success" is, I contend, a blunt instrument. How blunt is of course at the heart of this debate, and a topic with many facets.
None of these are claimed as a disproof, but rather for scoping and clarification.Petītiō principiī is generally accounted a fallacy. You are postulating that evolution is incapable of accounting for the biosphere as support for a claim that evolution is incapable of accounting for the biosphere.
Would you agree with this logic/structure?
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