Theory 48/Organism/Brain evolution
Brain Size Is Demand Against Cost
The claim
Relative brain size is set by the ratio of cognitive demand to maintenance cost, so species with expensive brains need either more energy or fewer other costs.
01Mechanism
Neural tissue is metabolically expensive; expansion requires the ratio to shift through increased demand or reduced competing costs.
02Prediction
Brain size should track the ratio.
03Refutation
Brain size tracking ecology alone would remove cost.