Trachycarpeae palms as models to understand patterns of island biogeography and diversification

Abstract

Palms are iconic members of tropical flora and are representative of the vast diversity found in rain forests across the world. Outside of being fundamental for forest structure and function and for human well-being in many tropical countries, palms also emerge as models for evolutionary studies. Because of their long history, rich fossil record, and dispersal ability, palms have been suggested to track forest evolution and change through time. In this dissertation, I use various molecular and analytical techniques to show that palms are an excellent model for understanding patterns of biogeography and diversification in tropical forests. Results show that Miocene dispersal was a driving force in island diversification across the world from the Caribbean, to Southeast Asia, to Hawaii. Data also support that differential shifts in diversification are key to shaping diversity patterns on Southeast Asian islands and across Wallace's Line. At finer scales, results show the importance of hybridization in the diversification of island lineages. Together, this research defines important conclusions from Trachycarpeae palms and extends them to the understanding of islands and to tropical forests in general.