[ExI] Are Limited Lifespans An Evolutionary Adaptation? (BillK)

rex rex at nosyntax.net
Fri Jun 19 15:26:48 UTC 2015

Keith Henson <hkeithhenson at gmail.com> [2015-06-19 07:43]:
> On Fri, Jun 19, 2015 at 5:00 AM,   BillK <pharos at gmail.com> wrote:
> snip
> > The simulation shows "evolution favors shorter lifespans in
> > environments where resources are scarce and when pressures to
> > procreate are particularly intense".
> That's not surprising, but what is known with small stature races
> (pigmies) is that the growth process is chopped off by early sexual
> maturity.  Apparently the environment they are in kills them at a rate
> that requires early reproduction.

Well, short stature apparently has a selective advantage there, but
that doesn't imply they would disappear if the gene(s) for short
stature disappeared. Remember, genes are advantageous, or not, in
the context of other genes.

> > That might well not be the
> > complete answer. But traits that benefit species survival rather than
> > individuals seem likely.
> This has been logically dismissed by Dawkins and company back in the
> 70s.  Genes induce individuals to things that result in the survival
> and propagation of genes.  End of story.

I wish. The group selectionist camp isn't going to quit beating their
war drums anytime soon, and even E.O. Wilson recently converted to
belief in group selection.


> Our social nature seems to
> lead us to account for the world in terms of "traits that benefit
> species survival" but this completely fails to pass a logical
> examination.  "Hamilton's rule" does not change this.

No, it doesn't "completely fail," and that's the problem. There are
restrictive conditions under which group selection can theoretically
arise. These conditions are rigorous enough that demonstrating real
examples of group selection has been elusive, but their theoretical
possibility leads its advocates on the holy quest (sadly, more and
more "science" is taking on the trappings of religion).


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