Figure 2

Conditions favouring not fighting by Q2. Critical values of d for which not fighting (above the lines) or fighting (below the lines) is favoured by Q2 for various values of f, from equation {4}. Each line represents a value of relatedness (r = 0.1, 0.25, 0.5, 0.75 and 0.9, with r = 0.75 (full sisters) indicated by a thick line). For clone queens (r = 1), critical values are always 0, and not fighting is always favoured. Not fighting is favoured when relatedness is high or when Q1 is a better fighter.