"Doug Miller" wrote in message
m...
In article , "J. Clarke"
wrote:

I seem to recall that part of the problem with the Mesoamerican
civilizations and the wheel was that they did not have a large draft
animal
of any kind and that soil conditions were such that in the absence of
something with the brute force to pull a cart through the mud a man could
carry more on his back than in a wheeled conveyance.

That's obviously incorrect. Never mind large draft animals -- anyone who's
ever used a wheelbarrow or a two-wheel dolly knows that a man can carry
more
on a wheeled conveyance than he can on his back. You don't need draft
animals
to make wheels useful.

They were certainly protein-limited by their lack of domesticated animals.
Makes you think about the role of nutrition in civilization in a whole new
light, and the role of domestication in providing nutrition as well as a way
to haul it to storage.

I've read more than one case for the collapse of the Maya based on
nutrition. The cultivation they seem to have had down pretty well, with the
same sort of mound and ditch found elsewhere, but of course they didn't have
the variety of protein in their diet to remain free of disease without some
meat.