Evolutionary–developmental (evo-devo) dynamics of hominin brain size
Abstract
Brain size tripled in the human lineage over four million years, but why this occurred remains uncertain. Here, to study what caused this brain expansion, I mathematically model the evolutionary and developmental (evo-devo) dynamics of hominin brain size. The model recovers (1) the evolution of brain and body sizes of seven hominin species starting from brain and body sizes of the australopithecine scale, (2) the evolution of the hominin brain–body allometry and (3) major patterns of human development and evolution. I show that the brain expansion recovered is not caused by direct selection for brain size but by its genetic correlation with developmentally late preovulatory ovarian follicles. This correlation is generated over development if individuals experience a challenging ecology and seemingly cumulative culture, among other conditions. These findings show that the evolution of exceptionally adaptive traits may not be primarily caused by selection for them but by developmental constraints that divert selection.
Citation
Gonzalez Forero , M 2024 , ' Evolutionary–developmental (evo-devo) dynamics of hominin brain size ' , Nature Human Behaviour . https://doi.org/10.1038/s41562-024-01887-8
Publication
Nature Human Behaviour
Status
Peer reviewed
ISSN
2397-3374Type
Journal article
Description
This work was funded by a European Research Council Consolidator Grant to A. Gardner (grant no. 771387).Collections
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