A Model of Correlated Evolution

Abstract

We introduce a model of biological evolution inspired by the Bak and Sneppen (BS) model. Microscopic dynamical rules are modified with respect to the BS model in order to account for predator-prey and competitor correlations. We perform numerical simulations of the system and compare them with both a mean field equation and a mean field simulation. The model is in a new universality class of self-organized critical behavior, and in addition shows a non-trivial fitness probability distribution. I. INTRODUCTION Much attention has recently focused upon non equilibrium systems displaying selforganized criticality (SOC), a concept introduced by P. Bak, C. Tang and K. Wiesenfeld [1]. SOC systems appear to be widespread in nature, including sandpiles [1], earthquakes [2], creep phenomena [3], material fracturing [4], fluid displacement in porous media [5], interface growth [6] and river networks [7]. Recently Bak and Sneppen (BS) [8,9] introduced a SOC model describing an ecosystem of interac..