X-Message-Number: 12816
Date: Mon, 22 Nov 1999 07:28:52 -0400
From: Rand Simberg <>
Subject: Evolution and Long Life

At 05:00 AM 11/22/99 -0500, John Clark wrote:

>    >>Me:
>    >>He can not find any down side to the mice at all but he speculates 
>there must
>    >>be one someplace because otherwise evolution would already have found 
>this fix;
>
>Rand Simberg <> in #12806 Wrote:
>
>    >I would conclude from this statement that he doesn't understand
evolution.
>    >From the standpoint of evolution, there is nothing broken to "fix."
There
>    >is no obvious benefit to the mouse genotype from in having the phenotypes
>    >live longer than they already do,
>
>That's not what I would conclude. I would conclude that long life for mice 
>would
>be an evolutionary advantage and the advantage is obvious, it just isn't 
>very big;

I guess it's not obvious to me, at least from the standpoint of the gene.
Can you enlighten me?

>it would not be worth even a small reduction in the fertility rates of young 
>mice.
>At least it wouldn't be worth it from evolution's point of view, the mice 
>may have
>another opinion on the subject.

Yes, that was my point.

And Jan Coatzee wrote:

>There is usually a direct relationship between an animal's development
>time from birth to being a mature or adult animal. 

Yes.

>If one extend the
>life span of an animal you will automatically increase this
>developmental time. 

This does not follow.  You are confusing cause and effect with correlation.

>This means in the case of most animals they can not
>survive to become adults and hence the extinction of the specie. Only
>the human specie can get away with that. Maybe one day humans will live
>a 1000 years but they will have to spend 100 years of that as teenagers.

There is no reason for this.  We spend a certain percentage of our lives as
adults because that's all out genes need--not because there's any physical
requirement to do so.  One could easily have a life space of hundreds, even
thousands of years, with the same adolescence time as current humans--there
are no physical laws preventing it.

>I don't think one can survive that long as a teenager. Neither could the
>parents handle a teenager for a hundred years. Thus the present ratio of
>teenage years to life span may be the optimum.

No, the present ratio is optimum only to the gene--we can fix that.  As you
point out, the ratio would have to decrease dramatically with artificially
longer-lived individuals.

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=12816