Re: 2nd law clarifications

On 03/01/2025 12:24, MarkE wrote:

On 3/01/2025 5:13 am, Ernest Major wrote:

On 02/01/2025 06:53, MarkE wrote:

Are these statements correct? Could they be better expressed?
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Local entropy can decrease in an open system with an input of free energy.
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Free energy alone is not sufficient to maintain or further decrease low local entropy: an energy capture and transformation mechanism is also needed.
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Extant life *maintains* low local entropy through its organisation and processes.
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Evolving life *decreases* low local entropy through the ratcheting mechanism natural selection acting on random mutations in instances where that evolution increases functional complexity and organisation.
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There is no other known mechanism apart from natural selection that does this. For example, neutral drift alone increases entropy.
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It is difficult to operationalise the concept of irreducible complexity, as that necessitates a principled definition of system, part and function. But if you pass over that point, there are at least three classes of paths (exaption, scaffolding, coevolution) whereby irreducibly complex systems can evolve. I suspect that the last is the most frequent, and that it can be driven by drift as well as by selection. If you are equating an increase in functional complexity and organisation with a decrease in entropy, then this would negate a claim that neutral drift always increases entropy.
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 What I would say more confidently is, "For example, neutral drift alone increases disorder."

While chopping evolutionary processes into 2 categories (variation and differential reproductive success), or 4 categories (mutation, gene flow, selection and drift), or more, is useful for explaining the overall process, it is necessary to consider the processes in concert when evaluating the capabilities of evolution. While I consider the claim that neutral drift alone increases disorder to be at best unproven, it is a diversion from the question as to the contribution of neutral drift to constructive disorder. (For example does neutral drift, by opening up a greater amount of sequence space, make natural selection more effective?)

 More precisely, if a population fixes neutral and near-neutral mutations over time through drift, with no selection acting, the net effect over time will be devolution, i.e. a loss of information and functional complexity. The end state will be extinction.

Consider a neutral change that causes a protein to attach to another protein, without effecting its functionality. What is to prevent a further series of neutral changes resulting in it being unable to perform its function unless attached to the second protein. Is that not an increase in complexity?

 Does this necessarily mean entropy will increase? It would seem so.
 

There are proposals that in the presence of energy flows matter arranges itself into structures (such as life) that increase the rate of entropy production.
--
alias Ernest Major