Emergent phenomena only belong to biology

Abstract

This rather philosophical paper discusses the necessary three ingredients which together allow a collective phenomenon to be described as "emergent". First the phenomenon, as usual, requires a group of agents entering in a non-linear relationship and entailing the existence of two semantic descriptions depending on the scale of observation. Second this phenomenon has to be observed by a mechanical observer instead of a human one, which has the natural capacity for temporal and/or spatial integration. Finally, for this natural observer to detect and select the collective phenomenon, it needs to do so in rewards of the adaptive value this phenomenon is responsible for. The presence of natural selection drives us to defend, with many authors, the idea that emergent phenomena can only belong to biology. After a brief philosophical plea, we present a simple and illustrative computer thought experiment in which a society of agents evolves a stigmergic collective behavior as an outcome of its greater adaptive value. The three ingredients are illustrated and discussed within this experimental context. © Springer-Verlag Berlin Heidelberg 2007.