> I have read that in nomadic pastoral cultures in Asia, when a
>   person reaches an age where he or she can no longer keep up with
>   the migrations of the group and do meaningful work, the accepted
>   practice is for that person to *stay behind* and die of exposure.
>
FWIW, some time ago I read about an Inuit folk tale that tells the story of 2
female elders left behind to fare for themselves on the tundra due to the lack of
food for the tribe.  Folk tales, while not necessarily absolute truth, are often
crafted for teaching purposes.

Pax,
Phyllis