Untangling Gloxinieae (Gesneriaceae). II. Reconstructing Biogeographic Patterns and Estimating Divergence Times Among New World Continental and Island Lineages

Abstract

Gesneriaceae tribe Gloxinieae is a diverse clade of approximately 19 genera and 215 species. As with many tropical lineages, patterns and timing of diversification are poorly understood. This is a particular difficulty in groups such as the Gesneriaceae that have no fossil record. Here we explore maximum likelihood and Bayesian inference of phylogenetic relationships in the tribe based on nuclear, chloroplast, and morphological data sets, use Fitch parsimony optimization (FPO) and dispersal vicariance (DIVA) analyses to explore biogeographic patterns in the Gesnerioideae, and use penalized likelihood calibrated by geological events in the Caribbean and South America to explore timing of movement of lineages among Caribbean, Central American, and South American land masses and islands. Likelihood and Bayesian analyses increase support of previous hypotheses of relationships using parsimony and provide additional resolution in some parts of the phylogeny. FPO and DIVA analyses suggest that the most likely scenario for movement among Central American, Caribbean, and South American areas was either an early dispersal to Central America and the Caribbean prior to diversification of the Gloxinieae clade with subsequent back dispersal to South America, or the ancestor of the Gloxinieae had a broad distribution across Central America and Andean/western South America. Estimations of the timing of movement of these lineages among these land masses suggests that the Greater Antilles/Aves Ridge landbridge likely played a role in dispersal events and that the Gloxinieae/Gesnerieae lineage likely arrived in the Central America/Caribbean zone at least 26 million years ago.