Historical biogeography of Vochysiaceae reveals an unexpected perspective of plant evolution in the Neotropics.

Abstract

Despite the fast pace of exploration of the patterns and processes influencing Neotropical plant hyperdiversity, the taxa explored are mostly from large groups that are widely distributed, morphologically diverse, or economically important. Vochysiaceae is an example of an undersampled taxon, providing an excellent system for investigating Neotropical biogeography. We present a phylogenomics-based hypothesis of species relationships in Vochysiaceae to investigate its evolutionary history through space and time. We inferred a phylogeny for 122 species from Vochysiaceae and seven other families of Myrtales. Fossils from four myrtalean families were used to estimate the divergence times within Vochysiaceae. Historical biogeography was estimated using ancestral range probabilities and stochastic mapping. Monophyly of all genera was supported except for Qualea, which was split by Ruizterania into two clades. Vochysiaceae originated ~100 mya, splitting into an Afrotropical and a Neotropical lineage ~50 mya, and its ancestral range is in the area currently occupied by the Cerrado. The most recent common ancestor of Vochysiaceae + Myrtaceae had a West Gondwanan distribution, supporting a South American + African ancestral range of Vochysiaceae. On a global scale, geographic range reduction was the principal biogeographic event. At a finer scale, initial range reduction was also important and the Cerrado region was the most ancestral area with multiple colonization events to the Amazon, Central America, and the Atlantic Forest. Colonization events occurred from open areas to forest vegetation, an unusual finding regarding the evolution of plants in the Neotropics.