The Bak–Sneppen Model: A Self-Organized Critical Model of Biological Evolution

Abstract

Recently, Bak and Sneppen proposed a simple model, the Bak–Sneppen (BS) model, as a coarse-grained description of biological evolution. It has attracted a lot of attention from interdisciplinary statistical physics community, for its simple model definition but extremely rich properties to be explored. The aim of this paper is to give a pedagogical and update review of this fast-developing topic. The emphasis is on the mechanism by which the BS model approaches the self-organized critical state, the universal properties of the system at criticality, and the relation with other topics, such as directed percolation, random walk, and a few self-organized critical models.