Minds, mechanisms and interaction in the evolution of language

Dr Marcus Perlman will be speaking at the Minds, Mechanisms and Interaction in the Evolution of Language, a workshop that he helped to organize at the Max Planck Institute for Psycholinguistics, 21-22 September 2017.

Abstract

The great apes – but not humans – all possess laryngeal air sacs, indicating that these were lost sometime over hominin evolution. Understanding why human ancestors lost their air sacs may provide clues to the evolution of speech. However, little is known about their function in extant great apes. In this talk, I explore the hypothesis that gorillas use their laryngeal air sacs to produce the staccato ‘growling’ sound of the male chest beating display, as well as other similar sounding ‘whinny’ vocalizations. These vocalizations are predominantly, but not exclusively, produced by males. I propose that great apes use their air sacs for vocalizations and displays related to size exaggeration for sex and territory. Thus, changes in social structure, mating, and sexual dimorphism, rather than evolutionary pressures directly related to the advent of speech, may have led to the obsolescence of the air sacs and their loss in hominin evolution.

The main hypothesis of the talk was sparked from this video clip of the silverback Kingo, recorded in the 2005 BBC Earth documentary Secret Gorillas of Mondika. You can also read the resulting article, published in the Journal of Language Evolution.