Genomics and biogeography of Physalideae (Solanaceae): integration of molecules, morphology and fossils to resolve the evolutionary history of the physaloids

The nightshade family, Solanaceae, at once illustrates the common challenges of molecular dating and presents a prime opportunity for expanding knowledge of biogeography and evolutionary history. Its most widely diverse tribe, Physalideae, contains roughly 300 species mostly distributed in South America, half of them with fruit key innovations known as the inflated fruiting calyx. The same structures are present in the oldest fossils of the family, recently discovered in the south of South America, reinforcing the idea of this area as the ancestral zone of origin and diversification for Solanaceae. After decades of molecular phylogenetics and fossil discoveries, I aim to introduce an integrative approach to disentangle the evolutionary and biogeographic history of the physaloids in the light of fossils, morphology, and museum genomics. To approach this, I will first infer a calibrated total-evidence phylogeny for the Physalideae including fossils and extant taxa. Building on these results, I will estimate diversification rates to test whether phenotypic changes in the fruiting calyx inflation affected them. Finally, and also using the calibrated phylogeny, I will reconstruct the ancestral areas of distribution of Physalideae, and I will test whether there is a correlation between the inflated calyx and the macroevolutionary dispersal rates. The convergence of genomics, paleobotany, and evolutionary morphology will allow us to test if the inflation of the fruiting calyx may have spurred the diversification and distribution of physaloids over the Americas and across continents, shaping the biogeographic patterns we see today.