Segregation in an interacting particle system

We present a lattice:rn system,m composed nf three kinds;of particles which interact following a rule combining the contact process with Rock-Paper-Sc issors game. Depending on value of a parameter, this system naturally evolv es into a specific pattern, where segregation of three species occurs. We d iscuss that such a segregation phenomenon associates with a habitat isolati on of biospecies. (C) 2000 Elsevier Science B.V. All rights reserved.