Criterion for Altruists selection. ( a) fixation probabilities πs (red squares) and πA (blue circles) as a function of selection pressure , for Nf = 100 and . Values are obtained by numerically solving eq.(8). Solid lines are theoretical values (eqs. 13,14). Increasing Ni are indicated by the arrow. (b) equilibrium selection pressure for which πA = πs for multiple combinations of and , as a function of relative population increase, obtained numerically. The solid line is the theoretical value (eq.15).
Houchmandzadeh and Vallade BMC Evolutionary Biology 2012 12:61 doi:10.1186/1471-2148-12-61