Fig. 3: Scatterplots showing the relationships from PGLS models of SSD regressed against directional change for each sex.

Females are shown in blue and males in red across all four tetrapod clades, with 95% confidence intervals represented by shading. Directional change describes the total amount of change along a branch that is attributable to directional effects on the natural log scale. Therefore, a directional change of 2 corresponds to a 7.38-fold increase in size. The yellow horizontal lines represent no SSD (females and males have equal sizes). Positive values (above the yellow line) represent species where females are larger than males and negative values (below the yellow line) represent species where males are larger than females. Icons from PhyloPic.org under a CC0 1.0 license: Panthera leo, Margot Michaud; Turdus pillaris, Sharon Wegner-Larsen; Varanus komodoensis, Steven Traver; Hyla versicolor, Will Booker.