Re: West Virginia creationism

On 13/04/2024 19:26, Bob Casanova wrote:

On Sat, 13 Apr 2024 16:17:50 +0200, the following appeared
in talk.origins, posted by Arkalen <arkalen@proton.me>:
 

On 13/04/2024 01:58, Bob Casanova wrote:

On Fri, 12 Apr 2024 11:04:15 -0700, the following appeared
in talk.origins, posted by Vincent Maycock
<maycock@gmail.com>:
>

On Fri, 12 Apr 2024 12:41:29 -0400, Ron Dean
<rondean-noreply@gmail.com> wrote:
>
<snip>

In the most cases where adaptations and minor evolutionary changes are
observed it's not because new information is added to DNA, but rather
there is a loss of information.
>
https://www.nature.com/articles/s41598-024-57694-8
>
Bad mutations seems to be the rule.

>
*Most* mutations are harmful, but to disprove evolution you need to
show that *all*  mutations are harmful -- those rare beneficial
mutations can be selected by and amplified through natural selection,
resulting in better-functioning organisms.
>

As I understand it, most mutations are neutral; the
beneficial and harmful ones are (approximately) equal in
number, and are far outnumbered by the neutral ones. But
don't expect your correspondent to accept any of that.

>
>
I understand the same thing on most mutations being neutral but do you
have a cite on beneficial and harmful ones being approximately equal in
number? From first principles you'd expect that once a system is vaguely
optimized (which all life is), changes that are harmful should be more
likely than changes that are beneficial.
>

No, I don't; sorry. I only (vaguely) recall that being from
several comments here, some by people (unlike myself)
qualified by training to make such a statement. As I recall
it, the comments were to the effect of "About 98% of
mutations are neutral, with the balance fairly evenly split
between beneficial and harmful". Your point is well-taken,
however, and it's something I never considered. I suppose it
depends on just how optimized the system is *in a particular
environment*, and how the environment is changing, since I'd
guess few mutations are inherently either beneficial or
harmful.

A propos of nothing I just ran into this paper which seems to speak to the question:
https://academic.oup.com/genetics/article/168/4/1817/6059315
I think it confirms the idea that beneficial mutations are less frequent than deleterious ones; the thrust of the paper is that beneficial mutations are more frequent than usually thought but that still works out to under 10% for most of the numbers it actually gives. There is one exception which I wonder might be the source of the commenters you remembered, where apparently one paper found the half-and-half distribution you describe in a mutation-accumulation experiment in Arabidopsis Thaliana.
snip