In a message dated 98-10-26 09:13:40 EST, you write:

<< For
 instance, 10% of the Bushmen are 60 years old or more; that has to be
 compared to industrialized countries, where the figure is no more than
 about 20%.
  >>

Jean Louis,

Our modern dogs seem to live far longer than their wild relations, despite
horrible diets.  I imagine the stress of environments, etc., desire for life,
etc., effects longevity as well.  I remember seeing one show on an African
tribe years ago.  There were two 'old' men who were said to be in their 80's
and 90's.  They remembered the process for making the old smelting pits, and
they helped at their age.  They'd sit comfortably on the ground like children.
Healthy old men.  I imagine the strong survive and the weak die.

Aaron