Fig. 5. Conceptual diagrams illustrating the evolutionary alternatives of mutual convergence, mutual divergence, and one-sided convergence (“advergence”).

Dashed arrows indicate the direction of evolutionary change. Left (A, D, and G): Mutual convergence in focal taxa (focal taxa, gray circles) with reciprocal transfer of pattern features (e.g., forewing band shape versus wing color) between two clades (1 and 2, respectively black versus gray outlines). Middle (B, E, and H): Reversed polarity with mutual divergence from the focal taxa. Right (C, F, and I): Advergence by one clade onto another (13). Asterisks indicate new derived patterns (feature combinations). When expressed in terms of the phenotypic distance from the focal taxa (G to I), mutual convergence (G) is characterized by a decreasing distance along the arrow of evolutionary change in both clades. Mutual divergence (H) is characterized by a increasing distance in both clades. Advergence (13) is characterized by a decreasing distance (and a greater distance traveled) in one clade (I).