Error, population structure and the origin of diverse sign systems

Evolutionary models of communication are used to shed some light on the sel ective pressures involved in the evolution of simple referential signals, a nd the constraints hindering the emergence of signs. Error-prone communicat ion results from errors in transmission (in which individuals learn the wro ng associations) and communication (in which signs are mistaken for one ano ther). We demonstrate how both classes of errors are required to generate d iversity and subsequently impose limits on the sign repertoire within a pop ulation. We then explore the influence of geographic structuring of a popul ation on the evolution of a shared sign system and the importance of such s tructure for the maintenance of sign diversity. Deceit tends to erode conve ntional signs systems thereby reducing signal diversity, we demonstrate tha t population structure can act as a hedge against deceit, thereby ensuring the persistence of sign systems. (C) 2000 Academic Press.