PT  - JOURNAL ARTICLE
AU  - Mauricio González-Forero
TI  - Evo-devo dynamics of hominin brain size
AID  - 10.1101/2023.03.20.533421
DP  - 2023 Jan 01
TA  - bioRxiv
PG  - 2023.03.20.533421
4099  - http://biorxiv.org/content/early/2023/08/28/2023.03.20.533421.short
4100  - http://biorxiv.org/content/early/2023/08/28/2023.03.20.533421.full
AB  - Brain size tripled in the human lineage over four million years, but why this occurred remains uncertain. To advance our understanding of what caused hominin-brain expansion, I mechanistically replicate it in-silico by modelling the evolutionary and developmental (evo-devo) dynamics of hominin-brain size. I show that, starting from australop-ithecine brain and body sizes, the model recovers the evolution of brain and body sizes of seven hominin species, the evolution of the hominin brain-body allometry, and major patterns of human development and evolution. Analysis shows that in this model the brain expands because it is “socio-genetically” correlated with developmentally late preovulatory ovarian follicles, not because brain size is directly selected for. The socio-genetic correlation causing the recovered hominin brain expansion is generated over development by ecology and possibly culture. Thus, in this model, direct selection that does not favour brain expansion provides a force that developmental constraints divert causing hominin-brain expansion.Competing Interest StatementThe authors have declared no competing interest.