Gestures and Adaptive Niches

This proposal presents an evolutionary analysis of three types of co-speech gestures: symbolic emblems, indexical pointing gestures and iconic representational gesticulations. Synthesizing insights from a range of published sources in gestural studies, general linguistics and sign language linguistics, primate studies and analyses of biological evolution, these gestures are analyzed as evolved traits adapted to particular niches or roles within broader systems. Niche boundaries are comprised of an element’s distinct properties and functions, routes of learning and transmission and degrees of innateness and evolvability within populations. Rather than elements distributed along a flat productive-analytical continuum or as stages along diachronic pathways, these gestural traits are analyzed in terms of adaptive peaks and valleys with a landscape representing the broader system comprising human gesture and language. The same evolutionary processes are used to analyze gestures in speaking populations and the linguistic traits derived from gestures in signing populations. This approach offers new ways of approaching proposed linguistic universals and long-standing issues such as listability in sign languages, while offering a formal approach to gestures.