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Updated: Jul 18, 2026
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A Comparative Approach for Quantitative Cell Counting Studies in Widely Different Mammalian Brains
Published on: January 16, 2026
Metabolic costs of brain size evolution
Karin Isler1, Carel P van Schaik
1Anthropologisches Institut und Museum, Universität Zürich-Irchel, Winterthurerstrasse 190, 8057 Zürich, Switzerland. kisler@aim.unizh.ch
Biology Letters
|December 7, 2006
Summary
Brain size in mammals is linked to energy costs. This study shows a positive correlation between brain size and basal metabolic rate (BMR), highlighting energetics in brain evolution.
Area of Science:
- Comparative biology
- Neuroscience
- Evolutionary biology
Background:
- Evolutionary theories of brain size have shifted from energetics to social/ecological benefits.
- New data on basal metabolic rate (BMR) and brain size are available.
Purpose of the Study:
- To re-evaluate the role of energetics in mammalian brain size evolution.
- To investigate the correlation between BMR and brain size, controlling for body mass.
Main Methods:
- Comparative analysis of existing data on BMR and brain size in mammals.
- Statistical controls for body size effects.
Main Results:
- A significant positive correlation was found between brain size and BMR in mammals.
- Energetics is a crucial factor in maintaining a relatively large brain.
Conclusions:
- Mammalian brain size variation must account for the energetic costs of brain maintenance.
- Cognitive benefits alone are insufficient to explain brain size evolution.
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