Revisiting the phylogeny of Ficus (Moraceae): When Next Generation Sequencing corroborates Past Generation Botanists

Abstract

Despite their ecological and evolutionary importance, fig trees still lack a resolved phylogeny. We used multiple analytical approaches and 600 conserved RAD-seq loci collected across 40 representative species to infer phylogenetic relationships among the major clades of Ficus. Our results converged on a fully resolved phylogeny that contradicts previous hypotheses by not placing section Pharmacosycea sister to all other fig trees. Instead, we find that subgenus Sycomorus is sister to two clades, one comprising all other gynodioecious sections, and the other containing all monoecious sections. Our results corroborate earlier botanists hypotheses and provide a baseline for future classification. We infer the evolution of key traits (growth form, breeding system and pollination mode) and find that, contrary to previous hypotheses, the ancestor of extant fig trees was likely a gynodioecious and actively pollinated tree. Our results open new opportunities to explore diversification patterns in fig trees and better understand their mutualistic interaction with wasps.