Modeling Complex Adaptive Systems with Echo

Abstract

. Complex adaptive systems (CAS) consist of many interacting and adapting components. Echo is a computational CAS model in which evolving agents are situated in a resource-limited environment. Different views of the notion of species within Echo are compared to biological experiments on relative species abundance, specifically to Preston 's "canonical" lognormal distribution. To appear in: Complex Systems: Mechanism of Adaptation, R.J. Stonier and X.H. Yu (Eds), Amsterdam: IOS Press, September 1994, pp. 3--21. 1. Introduction Many interesting systems are difficult to describe or control using traditional methods. These include natural ecological systems, immune systems, economies and other social systems. One source of difficulty arises from nonlinear interactions among system components. Nonlinearities can lead to unanticipated emergent behaviors, a phenomenon that has been well documented and studied in physical, chemical, biological, and social systems as well as in some forms of ...