Multilevel Selection
Price Equation: Δz̄ = Cov(w,z)/w̄ + E(w·Δz)/w̄
Parameters
Groups:
12
Group benefit multiplier:
3.0
Within-group selfishness advantage:
0.5
Migration rate:
0.05
Restart
Pause
Price Equation Decomposition
Global cooperators:
—
Between-group sel:
—
Within-group sel:
—
Generation:
0
Between-group
: altruist groups have higher fitness
Within-group
: defectors free-ride on cooperators
Cooperation survives when between-group selection outweighs within-group selection