The Mesoscale Is Where Causal Power Peaks: Why Biology Operates at the Optimal Grain Size

Here's a claim with broad implications: biological systems have evolved to operate at a specific scale — the mesoscale — where causal emergence is maximized. Too fine-grained and you're overwhelmed by molecular noise. Too coarse-grained and you lose predictive specificity.

Cells, tissues, organs — each represents a natural level of coarse-graining where effective information peaks. Evolution discovered these scales through selection, not by calculation.

Question: Can we predict the optimal scale for a given biological function from first principles?