Brain size grows first in stable environments before changing ones
Big Brains and Changing Environments: Cause or Consequence?
Neural and Evolutionary ComputingArtificial Intelligence
Summary
Bigger brains cost a lot of energy, so scientists want to know why animals evolved them. This study shows that animals might develop large brains in stable environments first, not just in changing ones as some ideas suggest. Later, these bigger brains help animals survive better when their surroundings become unpredictable. The authors ran computer simulations where virtual agents evolved bigger brains in static settings before facing changing conditions, and those with large brains did better. This challenges previous beliefs and highlights that the history of evolution matters in brain size changes.
What this means in practice
- •For evolutionary biologists: Use simulated evolution models to test hypotheses about brain size changes under different environmental histories.
- •For artificial intelligence developers: Design AI agents that evolve adaptability by first optimizing in stable conditions before handling unpredictable scenarios.
Authors
Sian Heesom-Green, Jonathan Shock, Geoff Nitschke
Abstract
Large brains are metabolically costly, and associations with changing environments do not imply they evolved there, as the Cognitive Buffer Hypothesis (CBH) would suggest. They may instead evolve in stable conditions and later facilitate colonization of changing environments. Using neuro-evolution in an artificial seasonal foraging task, we compared agents evolving exclusively in changing environments to agents first evolved in static environments before transitioning. Results show that larger neural networks in dynamic environments arise mainly from prior static evolution, achieving superior performance under unpredictable changes. Our results challenge strict CBH predictions, provide agent-based (computational) support for a colonization-based account and highlight the role of evolutionary history in brain size evolution.