On Tue, 11 May 1999, Rick Strong wrote:

> > A couple of additional points that have been
> > mentioned previously that i think bear repeating are the consideration of
> > whether or not the evolutionary diet is optimum for those of us past
> > prime child rearing years.  That is, should we assume that a diet that is
> > best for a 22 year old is also best for a 52 year old?  Does  the
> > evolutinary process "care"  about us after procreation and child
> > rearing?

You know, the more I think about it the less I see anything
"evolutionary" about this diet.  Perhaps it is because I am
becoming more skeptical about neodarwinism every day, the more I
study the literature on it.

The question of which hominids were our actual ancestors is one
of the most hotly debated in all of science.  Research published
in the last week or so indicates that "mitochondrial Eve" lived
some 300,000 years ago, rather than 150,000 years ago, as
previously thought.  Or maybe she didn't exist at all.

So, if by "evolutionary process" we are referring to the
transition from some prehuman primate to a human primate, we
don't really know anything about it.  We don't know what that
prehuman primate was, or what it ate, or how long it lived.

If we look at the matter cladistically -- using the observable
similarities between humans and other primates, rather than
conjectures about common descent -- we do find that humans have a
rather longer life span than other primates.  I don't think we
have an explanation for it.

For example, take Ray's "reasonable" target life span of a
million hours, or 114 years. Based on observation of primates in
general, is there anything that would lead us to suppose that
this is in fact reasonable?  I don't know of any other primates
that live anywhere near as long as that.  Do we know of any
*human* population for whom such a life span is typical?  No.  In
fact, what little we do know suggests that it is exceedingly rare
for any human being to live so long.  Is this because of the
diseases of civilization?  No doubt they contribute to its
rarity, but there doesn't seem to be much evidence that
pre-civilized people were living that long, so that is unlikely
to be the whole story.

To get back to your question, I'd like to point out that
longevity in humans serves a purpose that it would not serve for
other primates.  Humans rely a great deal on extra-somatic
knowledge for their survival.  This is also called culture.
Other primates, and indeed all other species, relay mainly on
somatic knowledge, or instinct.  Until recently, all
extra-somatic knowledge was transmitted orally and stored in
living libraries: people.  The most important "volumes" in the
library would have been the elders, for the simple reason that
they had the most time to accumulate knowledge.

So my point is that longevity and culture-dependency are linked.
It is impossible to say which one caused the other. Indeed, it
seems necessary to have both, if either one is to mean much.

To end this rambling post then, I think a case can be made that
longevity is part of our distinctively human adaptation.  Walford
and the CRON researchers have a body of evidence that a lifespan
of 114 years is plausible given sharply reduced caloric intake.
It's plausible but by no means proven for humans, who do not live
in laboratories.  Other than that, it's very hard to know how
long a human should live.

Todd Moody
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