Theoretical considerations in the adaptation of animal communication systems.

Using concepts drawn from semiotic, the general theory of signs, and from the mathematical theory of communication, a theoretical framework is developed within which the problems relating to communication system adaptation may be defined and models of such adaptation constructed. The relationship between the semiotical notions of qualisign and legisign is used to define a concept of tolerance space that permits the statistical concept of equivocation to take on physical dimensions in the analysis of natural communication systems. For each of three central properties of the communication system (entropy, equivocation and semanticpragmatic relations) the components of the system that determine the property are identified and the ways in which these components might adapt to environmental changes are discussed.