On Sun, 25 Nov 2001 10:13:20 -0500, Paul Getty <[log in to unmask]> wrote:

>Our digestive systems are also set up for digesting meat..........so there
>is not one "THE" ecological niche for humans.
>

Yes, it's more the problem to digest some plant items.
The ecological niche is about the availability of food items.

For example chimps cannot survive in the savanna, because in a dry season
they lack fallback foods.
If some hominids can access undergroud roots there, with few competition
(only with some pigs and mole rats) then that's a ecological niche.
Which can be filled by creatures with the techniques or genetic adaption to
cope with the food. The more difficult to access or digest, the greater the
chance to be alone in the niche - and be successfull therefore.

The more unique the technique (like fire or stone tools) the less
competition, the more success.
They daytime bipedal moving gains access to more tubers and carrion.
Fire doubles the calories and scares off predators.
That's a niche, maybe the explanation for the success of h.erectus.

Amadeus