A cerebellar substrate for cognition evolved multiple times independently in mammals

Area of Science:

• Evolutionary biology
• Neuroscience
• Comparative anatomy

Background:

• Complex behaviors evolve independently across lineages.
• The cerebellum, particularly its lateral parts, is linked to higher cognitive functions in mammals.
• Understanding the neural basis of convergent evolution in cognition is crucial.

Purpose of the Study:

• To investigate if independent evolution of complex behaviors in mammals involved modifications to shared neural systems.
• To examine the role of the lateral cerebellum in the evolution of domain-general cognition across mammalian lineages.

Main Methods:

• Mapping the evolutionary diversification of the mammalian cerebellum.
• Correlating relative volumetric changes in lateral cerebellar hemispheres with cognitive measures.
• Analyzing patterns of parallel and convergent volumetric shifts in distantly related mammals.

Main Results:

• Relative volume of lateral cerebellar hemispheres correlates with domain-general cognition in primates.
• Mammalian cerebellum shows parallel and convergent volumetric expansion in distantly related lineages.
• These volumetric changes are independent of overall cerebellar size.

Conclusions:

• The cerebellum, a common neural system, may explain independent evolution of increased behavioral complexity in mammals.
• Multiple, independent neurodevelopmental remodeling events of the cerebellum likely occurred during mammalian evolution.
• Convergent evolution of cognition in mammals may be facilitated by selection on a shared, adaptable neural substrate.