Re: 2nd law clarifications

On Fri, 3 Jan 2025 09:56:16 -0600
RonO <rokimoto557@gmail.com> wrote:

On 1/3/2025 6:24 AM, 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?
>
>
Local entropy can decrease in an open system with an input of free
energy.
>
Free energy alone is not sufficient to maintain or further decrease
low local entropy: an energy capture and transformation mechanism is
also needed.
>
Extant life *maintains* low local entropy through its organisation
and processes.
>
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.
>
There is no other known mechanism apart from natural selection that
does this. For example, neutral drift alone increases entropy.
>

>
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.
>

 
What I would say more confidently is, "For example, neutral drift alone
increases disorder."
 
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.
 
Does this necessarily mean entropy will increase? It would seem so.
 

 

I see MarkE is back pushing his idee fixee that neutral drift
in evolution inevitably leads to degradation.

Please can he reread all the previous refutations.

It would be non neutral drift that would likely be associated with
increased disorder.  Even if something is selected against it can still
be fixed in a small population by factors not directly affecting the
trait under selection.  90% of a population might be wiped out by some
disease and the survivors may just, by chance, have a high frequency of
some deleterious allele that might get fixed by random chance.
 
Neutral drift is just neutral changes, it shouldn't result in any
increase in disorder because those changes are selected against.  Look
at the coelacanth it has been adapted to a specific environment for
hundreds of millions of years, and has changed very little, and yet
genetic drift in their DNA sequence and physical features invisible to
the environment have changed, but the outward physical appearance has
not degenerated.  Drift has occurred even as the morphology has been
maintained.  The skull may make nearly identical fossil impressions, but
when you look at the skull you observe that all the bones that make up
the skull have very different sizes and shapes, but still make the same
overall skull shape.  This is neutral drift.
 
Drift can result in loss of gene functions that are no longer needed in
certain environments.  The eyes in cave fish are an example, and even
that isn't neutral drift because the loss of eye function has selective
advantage because of the energy consumption of tissue that is no longer
needed.  Pigmentation loss in caves may be a better example, but
watching the nature shows and observing all the deep sea fish that
retain their eyes and bright colorations make me think twice about it.
 
Ron Okimoto
 

--
Bah, and indeed, Humbug