Fig. 4.

Potential evolutionary mechanisms underpinning the richness gradient in coral reef fish planktivores. (A) Mean net diversification rate per geographic cell (n = 2,800) in planktivorous lineages against distance from the IAA. The black line shows prediction from a generalized linear model with the respective R² value (top left). (B) Proportion of transitions toward planktivory per biogeographic province. Black points show mean proportions, and shading shows the interquartile range. Semitransparent points represent individual simmap simulations per province (n = 1,000). Provinces: central Pacific (CP), western Indian (WI), tropical eastern Pacific (TEP), eastern Atlantic (EA), and western Atlantic (WA). Colors in A and B depict a gradient of distance from the IAA, with red shades representing locations closest to the IAA and blue shades being farthest from the IAAc. (C) Dispersal rates from (orange) and into (purple) the IAA in planktivorous reef fish lineages. Black points underneath the posterior distributions represent modal values with respective 95% CI (n = 3,600 iterations).