Re: extropians-digest V4 #13

Harvey Newstrom (
Fri, 15 Jan 1999 13:15:08 -0500

> Cynthia Allingham wrote:
> I think some of the most striking evidence that humans are
> suppose to be meat eaters, comes from a comparison of the human
> digestive system with other species.
> One thing we know for
> sure, is that human beings are not designed to eat grains!

Please! I studied comparitive biology, and this chart is a joke. Any biologist will tell you that humans are omnivores. Our digestive system is somewhere in-between an herbivore's and a carnivore's. You can draw parallels to either. And as for grains, humans and all herbivores have the enzyme ptyalin in their saliva which is required to digest grains. Carnivores do not have this enzyme. Humans are obviously adapted to digesting grains.

This chart claims that humans always chew vertically and never rotary? Mastication is not important in human eating habits? Humans get no digestive benefit from intestinal bacteria? Human digestion works at 100% efficiency? And it is impossible for a human to live without animal protein in its diet?

Why does it compare digestive track length as a ratio to the whole body, but compares actual size of stomachs? Why the emphasis on colon size, rectum size, and feces size? Couldn't we just choose a rabbit for our herbivore and get a small colon, small rectum and small feces?

What about the comparisons that the chart doesn't show:

Carnivores                      Herbivores      Humans
==========                      ==========      ======
Perspires through tongue        through skin    through skin
Sharp claws                     no claws        no claws (or vestigial)
Sharp pointed fangs             no fangs        no fangs (or vestigial)
Acidic saliva                   alkali saliva   alkali saliva
no enzyme ptyalin               enzyme ptyalin  enzyme ptyalin 
strong HCl acid in stomach      1/20th strong   1/20th strong
no molar teeth                  molar teeth     molar teeth

The fact is, humans are omnivores. They evolved away from meat eating into something inbetween an omnivore and an herbivore. Transhumans can eat whatever they want, as long as they get enough of each nutrient in whatever diet they choose.

Harvey Newstrom <> <>
Author, Engineer, Entrepreneur, Consultant, Researcher, Scientist.