Re: Alex's gibbon-like CA

Phil Nicholls (
Thu, 16 Nov 1995 04:23:36 GMT (H. M. Hubey) raged:

> (Phil Nicholls) writes:

>>that if two species attempt to occupy the same niche they will compete
>>for limiting resources. There are three possible outcomes:

>>[1] One species will become extinct.
>>[2] One species will migrate
>>[3] One or both species will adapt in a way that avoides competition.
>>This is called niche partitioning.

>I think this is overdone.

>I suspect that this comes from someone's differential
>equation models for two species along the lines
>of Lotka and Volterra models.

Very good!. However, the Lotka - Volterra equations were derived for
predator-prey relationships. The equations for modeling competitive
interactions were developed by Gause and Witt. Competive exclusion
itself is derived from empirical data collected in experiments by
Gause, Slobodkin and many others. The axom above is known as the
competitive exclusion principle and was formulated by Hardin (1960).

>I don't see how anyone can prove this. A niche is a difficult
>enough concept to begin with, and pushing these ideas like
>axioms of a system can be dangerous to health :-)..

Well, we both know that science isn't about proof, don't we?

There are many parameters in an ecological niche. If two species
occupy the same niche then all of these parameters will be the same.
In every environment there is always at least one limiting resource
which will provide the a basis for competition. The experiments by
Gause and others show that competition usual results in the extinction
of one of the competing species. Other option is co-evolution and
niche partitioning.

>I don't believe that there does not exist two species of
>fish, for example, that don't feed on the same species of
>fish or the same algae.

There are many other aspects of a niche besides diet.

>In order to prove I'm wrong someone would have to check the
>huge number of species of fish that exist, clearly
>next to impossible.

Sort of like proving that the sun always rises in he east, no? Again,
the competitive exclusion principle is based on empirical data. I can
provide you with citations if you want.


> Regards, Mark

Phil Nicholls
"To ask a question you must first know most of the answer"
-Robert Sheckley