Human Origins: Hidden Nonlinear Dynamics in Brain-Culture Coevolution

Humans take communication, culture, and cooperation to unique extremes within the animal kingdom, a characteristic that evolutionary anthropologists have called behavioural modernity. Our species readily masters language, using it to exchange and collectively manage cultural traditions of greater behavioural complexity than any lone individual can produce within a single human lifetime. Moreover, these feats are accomplished and sustained among relatives and strangers alike, despite the possibility and advantages of free-riding upon the collective resources and knowledge of others. Up until recently, these three facets of behavioural modernity have been addressed as separate areas of enquiry, with comparative psychologists searching for language-like capabilities in nonhuman animals, cultural evolutionists investigating the origins of cumulative cultural evolution, and behavioural ecologists looking to explain mechanisms of cooperation among various human societies. In this thesis, I evaluate the proposal that these seemingly separate processes might actually depend upon a single phenotypic adaptation for behavioural modernity: cognitive modernity. Using models from the fields of computational neuroscience and cultural evolution, I demonstrate that cognitive modernity can evolve through a parsimonious process, only requiring that the mammalian neocortex increase in volume alongside the cooperative exchange of cultural knowledge. Furthermore, I show that when these two processes of encephalisation and cooperation are interlocked in coevolutionary embrace, they can produce two distinct regimes that resemble observed differences in the cultural behaviour of human and nonhuman animals. When natural selection favours small scales of cooperative information sharing, storage requirements of cortices are less, cognitive modernity does not emerge, and cumulative culture is limited. However, when diffuse information sharing is favoured, large cortices evolve to store more adaptive knowledge, cognitive modernity emerges, and cumulative culture comes to involve the open- ended recombination of tools, symbols, and institutions that cognitive modernity provides.<p></p>

Author dc:creator

• Andoni Soteri Edwin Sergiou (21040118)

• cumulative culture
• human evolution
• brain evolution
• cultural evolution

Statement dc:rights

• All rights reserved

Identifier

10779/exe.31244977.v1

OAI identifier oai:identifier

oai:figshare.com:article/31244977