> At 16:35 2000-03-29 -0500, gts wrote:
>
> >This means that the forces of evolution.. natural selection.. have
> >engineered our bodies to work well until the age at which we likely to
have
> >procreated. Nature's implied warranty gradually becomes null and void
with
> >each year that passes after our sexual prime.
>
> Be careful here. Homo Sapiens is a highly social species. Old persons
> have importance for the procreation of the younger members of the group.
> They supply information and help collecting food, and more.

I agree Hans. This is one reason that I wrote that nature's implied warranty
"gradually" becomes null and void. It shouldn't happen entirely and
instantaneously after reaching our sexual peak because as you point out
there is some value to mothering and fathering and to other nurturing
activities. Another reason would be that we do not instantly lose the
ability to procreate.

However eventually older people become the competitors of young people for
food and other resources and it is in the interest of our genes that the
young people win the battle. Mother nature has relatively little interest in
creating or supporting people beyond the years of child-rearing. In general
this means we should put less faith in mother nature as we grow older.

"Less faith in mother nature as we grow older" as it applies to this
discussion, means less faith in the ability of the body to obtain proper
nutrition from natural food sources. Relatively little reason exists to
think evolution has equipped us with a natural ability to live well for our
entire ~80 year lifetimes on an unsupplemented paleodiet or on any diet of
any kind. In theory nature's evolutionary promise should begin to expire
rapidly around age 40 or so, an age which I suspect was probably considered
fairly old for a Cro-Magnon. I think it is no coincidence that this is
approximately the age at which many modern people really begin to first
notice themselves starting to "grow old".

-gts