Figure 2From: Selection for altruism through random drift in variable size populations Fixation probabilities. Comparison of analytical solution (12) (solid lines) to numerical solution of eq.(8) for increasing selection pressure indicated by the arrows: N f s ¯ = 0.02 , 0.05 , 0.1 , 0.2 , 0.5 , 1 , 2 . N f = 100, N i = 90.Back to article page