title: Memory and self-induced shocks in an evolutionary population competing for limited resources.
abstract: We present a detailed discussion of the role played by memory, and the nature of self-induced shocks, in an evolutionary population competing for limited resources. Our study builds on a previously introduced multiagent system [Phys. Rev. Lett. 82, 3360 (1999)] which has attracted significant attention in the literature. This system exhibits self-segregation of the population based on the "gene" value p (where 0< or =p< or =1 ), transitions to "frozen" populations as a function of the global resource level, and self-induced large changes which spontaneously arise as the dynamical system evolves. We find that the large, macroscopic self-induced shocks that arise are controlled by microscopic changes within extreme subgroups of the population (i.e., subgroups with "gene" values p approximately 0 and p approximately 1).
authors.affiliation: Physics Department, Oxford University, Parks Road, Oxford, QX1 3PU, United Kingdom. roland.kay@physics.ox.ac.uk
authors.forename: Roland
authors.initials: R
authors.lastname: Kay
authors.forename: Neil F
authors.initials: NF
authors.lastname: Johnson
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D005075:Biological Evolution; D003163:Competitive Behavior; D003198:Computer Simulation; D003247:Conservation of Natural Resources; D017753:Ecosystem; D005246:Feedback; D008568:Memory / Q000502:physiology*; D008954:Models, Biological; D008957:Models, Genetic; D015233:Models, Statistical; D011157:Population Dynamics