Historical Biogeography of Cuban Protium (Burseraceae)

The Burseraceae plant family is comprised of 750 species, and the genus Protium is the most speciose member in the New World with about 140 species.  A lingering question is how and when Protium arrived in South America.  The only known fossil was found in London, and determined to be from the Eocene, an epoch characterized by tropical rainforests as north as Greenland.  Recent molecular systematic work indicates that the evolution of many neotropical taxa occurred on a schedule conflicting with deep-time vicariant events.  One possibility is that as the world became cooler and drier, tropical rainforest plants slowly retreated towards the equator.  Protium may have crossed into South America via an island arc that likely existed around 20 to 30 million years ago in what is now Central America and the Caribbean Sea.  Cuba was likely attached to the North American plate at that time, and has since drifted in the Caribbean Sea.  There are five described species of Protium in Cuba. To determine relations among the species and trace their biogeographical history, we will extract DNA from Cuban Protium tissue and conduct molecular phylogenetic analyses using Bayesian analysis and maximum likelihood.  Results of this study will be used to determine how many times and when Cuban species of Protium colonized the island, uncover relations to both Old World and Amazonian species, and investigate the role Cuba plays in generating and preserving tree diversity in the Caribbean and the New World.