Supplementary material from "Evolutionary ecology of language origins through confrontational scavenging "

A dynamic model and an agent-based simulation model implementing the assumptions of the confrontational scavenging hypothesis on early protolanguage as an adaptive response of Homo erectus to gradual change in their habitat has been developed and studied. The core assumptions of the hypothesis and the model scenario are the pre-adaptation of our ancestors to occupy the ecological niche that they constructed for themselves by having evolved displaced communication and a rudimentary tool manufacture, two features allowing them to use a new, concentrated and abundant resource—megafauna carrion—on the savannas replacing arboreal habitats due to the drying climate of East Africa about 2Ma. The shift in diet requires coordinated cooperation by the hominin scavengers confronted with concurrent predators. Power scavenging compels displaced symbolic communication featuring a limited semantic range; syntax is not yet required. We show that phenotypic evolution on the accuracy of information transfer between cooperating hominins is a necessary and sufficient condition for the population of agents to survive the diet shift. Both the individual and the group fitness of the hominin horde increases with the accuracy of their protolanguage, with decreasing time allocated to foraging and thus more time left for culture.This article is part of the theme issue ‘Human socio-cultural evolution in light of evolutionary transitions’.