On Sat, 7 Dec 2002 08:31:23 +1000, Phosphor <[log in to unmask]> wrote:

>>"Comparative and experimental data show that modern >humans, common
>chimpanzees, gorillas, and orangutans show >close similarity in most
>features of gut anatomy as well as >pattern of digestive kinetics
>
>the apes can digest cellulose, we can't. seems a big difference to me. I
>guess that's why you haven't eaten a bowl full of forest leaves recently.

Cellulose digestion is done by bacteria in the ape gut,
not by the ape itself.
Humans have less such bacteria, but some are there, which *can* downgrade
cellulose to digestable items as well.
Since humans normally don't eat leaves for caloric purpose this doesn't
matter. Since humans do eat some leaves with the purpose to supply
essential nutrients (e.g. folate) they need a cellulose breakdown
facility.
Remember the taste of lettuce?

The amount of such bacteria varies of course with the diet the human eats.
Whoever eats little insoluble fiber (cellulose) of course hasn't enough
symbionts which do that job. Humans can even loose some kinds (strains) of
symbionts completely - a state called dysbiosis.

Humans normally live in symbiosis with their gut bacteria and they make up
as many cells as a human itself has.
What happens if the symbionts are lost, is what you, or a inuit, might
experience after a meal with lots of cellulose.
Like a big salad.
Much of it can remain undigested.

Has anybody found a source where the actual gut lenghts of a human, a
gorilla, a chimp, and a cat are listed?
I'd like to take a look at it myself.

I have found some comparison of a human, a wolf and a sheep, which is cited
from time to time. However this isn't a valid comparison.
Dogs are well able to digest starchy food (in contrast to cats).
Sheeps are ruminants, that's a completely different approach as a chimp has
for example.
Even Ward Nicholson (the one with the famous interview,
http://www.dfhi.com/interviews/nicholson.html ) stays somewhat diffuse
... you have to weight the gut and count the villi and so on.
So I'd like to see the data of human, gorilla, chimp, cat.    Anybody has?

regards

Amadeus S.