Fig. 2.

Relationships between C_max, I_max, and body mass. C_max and I_max are strongly positively associated (A) (marginal R² = 72%, conditional R² = 96%), but this relationship reflects their strong dependence on body mass (B and C) (marginal R² = 64 and 72%, conditional R² = 94 and 92%, for C_max and I_max, respectively). The size dependence of both traits is close to isometric based on OLS regression, but accounting for nonindependence with random effects for species and taxonomic group identity reduces the slopes to 0.75 for I_max and 0.6 for C_max. Black lines represent across-group patterns captured in the models by fixed effects, while gray lines represent phylum-level variation captured with random slopes and intercepts. Species-level variation is also captured by random intercepts. Variation in the relationships across environments (aquatic/terrestrial) and feeding dimension (surface/volume feeders) is minimal, and is shown in SI Appendix, Fig. S1.