The evolution of mammalian brain size

Smaers, Jeroen B. and Rothman, Ryan S. and Hudson, Daphne R. and Balanoff, Amy M. and Beatty, B. and Dechmann, D. K. N. and de Vries, Dorien and Dunn, Jacob and Fleagle, John G. and Gilbert, Christopher C. and Goswami, Anjali and Iwaniuk, Andrew N. and Jungers, William L. and Kerney, Max and Ksepka, Daniel T. and Manger, Paul R. and Mongle, C. S. and Rohlf, F. James and Smith, N. Adam and Soligo, Christophe and Weisbecker, Vera and Safi, Kamran (2021) The evolution of mammalian brain size. Science Advances, 7 (18). eabe2101. ISSN 2375-2548

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Relative brain size has long been considered a reflection of cognitive capacities and has played a fundamental role in developing core theories in the life sciences. Yet, the notion that relative brain size validly represents selection on brain size relies on the untested assumptions that brain-body allometry is restrained to a stable scaling relationship across species and that any deviation from this slope is due to selection on brain size. Using the largest fossil and extant dataset yet assembled, we find that shifts in allometric slope underpin major transitions in mammalian evolution and are often primarily characterized by marked changes in body size. Our results reveal that the largest-brained mammals achieved large relative brain sizes by highly divergent paths. These findings prompt a reevaluation of the traditional paradigm of relative brain size and open new opportunities to improve our understanding of the genetic and developmental mechanisms that influence brain size.

Item Type: Journal Article
Faculty: Faculty of Science & Engineering
Depositing User: Lisa Blanshard
Date Deposited: 17 May 2021 15:20
Last Modified: 09 Sep 2021 18:51

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