New insight into the phylogenetic and biogeographic history of genus Ficus: Vicariance played a relatively minor role compared with ecological opportunity and dispersal

Studies on the evolution of tropical taxa emphasize the role of vicariance and the break-up of Gondwana in explaining modern distributions. Earlier studies on figs (Ficus spp.) support this view. In the current study, we used an expanded sample (208 spp.) and improved molecular dating techniques to reconstruct the phylogenetic and biogeographic history of Ficus. Consistent with previous studies, our biogeographic analysis indicated that the ancestor of Ficus was present in Gondwana. However, a relaxed clock analysis relying on uncorrelated rates in BEAST suggested that the Neotropical section Pharmacosycea split-off in South America 86.67 Mya, and that other Ficus lineage ancestors originated in India. Most of the basal lineages appeared to have diverged following KT extinction, then rapidly diversified after India collided with continental Asia. The Afrotropical species most likely evolved initially in the Indian subcontinent then dispersed to Africa, either in the late Cretaceous of Madagascar or even later, following the Eocene collision of India with Asia. The Neotropical section Americana, either island-hopped to South America or took a northern route to the Americas through Europe prior to the terminal Eocene global cooling event. Ficus may have arrived in eastern Malesia following the collision of India with Asia, then widely dispersed thereafter. Given the wide ranges in our date estimates, several other scenarios are possible. However, contrary to earlier reports, our analyses suggest that vicariance played a relatively minor role compared with ecological opportunity and dispersal in the diversification of genus Ficus.