Self-organization and the Formation of Patterns in Plants

Abstract

Beloussov et al., the introductory article (IV.1 this Chapter), pointed out contrasting assumptions in positional information theory (PI) and in theory based on more epigenetic principles as expounded by Driesch. One key feature of PI theory, in addition to the mentioned use of privileged sites to establish a geometrical frame of reference for development, is that the relation between a control and the response to it need to be defined only by correlation. At any moment this gives PI theory enormous flexibility with regard to cause and effect. That is, a given positional value may be coupled to virtually any kind of activity. This feature can be considered a virtue because of the obvious versatility. This can also be considered a shortcoming because it places, at least temporarily, a black box between cause and effect. Control elements ideally have an explicit connection to the responding system. Also, what happens at one time needs to lead into what happens next. This normal behavior is hard to account for explicitly with a black box present in the causal chain. The theses in IV.1 thus makes plea for a rational explanation of the self-evolving and self-correcting properties of developing systems.