Macroevolution of defense syndromes in Ficus (Moraceae)

Recursive adaptations and counter-adaptations of plant-feeding insects are thought to have driven chemical and physical diversity in plant defenses. Among existing theories on defensive diversity, the syndromes hypothesis predicts that plants may evolve suites of covarying defense traits along evolutionary arms races with herbivores. We use the large, phenotypically diverse angiosperm genus Ficus (Moraceae) to test the major predictions of this hypothesis: i) plant species will form distinctive combinations of defensive traits; ii) these traits will be correlated within each syndrome. Trait combinations need not map well onto phylogenies because plant species can converge onto similar trait values, but strong phylogenetic signal driven by selection (as opposed to drift) suggests roles for escalation and co-evolution. Finally, Ficus species with complementary combinations of defenses will be less susceptible to insect damage and harbor distinct insect communities. We quantified susceptib...