Figure 1
From: Selection for altruism through random drift in variable size populations
Variable carrying capacity.
(a): A community where the carrying capacity is an increasing function of altruist number, varying from N i when the population is composed only of selfish individuals to N f (N f > N i ) when only altruists are present. (b) Two examples of random walks describing the stochastic behavior a such a system (transition probabilities 4–7), where m,n are the number of selfish and altruistic individuals. Red line: loss of S’s; Blue line: loss of A. A Moran process in this scheme corresponds to a random walk constrained to remain on an anti-diagonal line.