Abstract

Recent developments in comparative methods are providing unprecedented insights into how biological traits evolved through time. I apply these methods to the mammalian brain, with a particular focus on primates. The results overturn some simplistic ideas about brain evolution that have taken root in the literature, providing a more complex and nuanced picture in which different kinds of structural change occurred at different times in response to different selection pressures. Evolutionary rates of change in the size of the brain and its components were enormously variable. Rather than simply progressive expansion of frontal brain regions (as commonly assumed), we find complex patterns of mosaic change across both cortical and sub-cortical regions. The cerebellum emerges as a key structure in the evolution of human cognition and behaviour, and may have been crucial in the evolution of our facility for understanding and producing syntactically structured behaviour, including tool use and language. Postnatal development was key to these changes, helping to explain the extended period of immaturity in humans and other great apes. The complexity of the patterns of brain evolution contradict single-factor hypotheses and in particular undermine attempts to explain cognitive evolution as the product of selection on some single generalised capacity such as ‘executive control’. Instead, the results suggest that the brains of different species support specialized forms of embodied cognition closely associated with their sensory-motor adaptations.

About the speaker

Robert Barton, professor, Department of Anthropology, Durham University.

Rob Barton has an interdisciplinary background in evolutionary biology, psychology and anthropology. He studied the behavioural ecology of baboons before moving on to phylogenetic comparative studies of primate evolution and adaptation - focussed mainly on brain evolution and its relationship to ecology, behaviour, cognition and life histories. His work has explored the complex, mosaic evolution of brain structure and overall  brain size. Rob is currently Professor of Evolutionary Anthropology at Durham University in the UK, where he also led the Institute of Advanced Study for several years. In 2019 he was awarded the Osman Hill medal for contributions to primatology.

Free of charge - All are welcome