Convergence and divergence in beach mice colour pattern. (a) Negative correlation between genetic distance and phenotypic distance in pair-wise comparisons among five beach mouse subspecies. The extreme points demonstrate (b) convergence and (c) divergence in colour pattern. The most distantly related subspecies, Perdido Key and Choctawhatchee beach mice, occupy similar-coloured sands and have similar lightness scores (see text), whereas the two most closely related subspecies, Alabama and Santa Rosa Island beach mice, occupy different coloured sands and have different lightness scores.