Request for info on software

[Phil Carver]

I am conducting research into the long run outcomes of economic and 
biological selection.  I am looking for some software that allows
the modeling of entities based on their relationship with other
entities. (eg parasitism, random events, resources, etc).
The model inputs would specify the relationships and have natural 
selection determine the "ecology."  Please Email me  at
PhilC at igc.apc.ofrg or post to this newsgroup.  Thanks in advance