Someone wrote that a person named Barker said:

'Evolution is completely indifferent to anything affecting death or
disease risk after the age of reproduction.'

Several anthropological studies have shown that grandmothers can contribute
to the reproductive success of their children by helping care for the
grandchildren, or by contributing to the household economy in general.  This
would suggest that any genetic factors contributing to long-term survival of
grandmothers would be selected for, long after their own days of reproducing
are over.

Also, remember that in humans, women can have children til they are 45-50,
and they need to survive about 15 years after the birth of the last child in
order for that child to have a good chance of surviving.  So that puts them
at 60-65 years of age already, before they are "after the age of
reproduction."  It isn't enough to just birth the baby.


Kathy Dettwyler
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