FAD facilitates the evolution of increased dispersal rates. Each cell shows the outcome of invasions of FAD or UNI modifier alleles. Modifier alleles are introduced at 50% to a population dispersing at a uniform rate of α = 0.3 (A and B) or α = 0.1 (C and D). If both FAD and UNI invasions were significantly more successful than expected by a neutral allele, the cell is white. If no strategy was successful, the cell is black. If only FAD was successful, the cell is light grey. If FAD was maintained at polymorphism but did not take over, the cell is dark grey. FAD facilitates the evolution of increased dispersal rates of α = 0.4 (A), α = 0.5 (B), α = 0.2 (C) and α = 0.3 (D) under a wider parameter range than UNI. The difference is particularly noticeable when there is a cost to dispersal (c > 0) and when the masking of deleterious alleles is not very low (h > 0.1). Qualitatively identical results were obtained for the introduction of FAD alleles at a frequency of 0.01 for a sample of the parameter range.