The distinctions between dispersal and vicariance are discussed and shown how they relate to geological history. Postulated theories on the tectonic origins and history of the Greater Antilles are reviewed, as well as possible climatic events that would affect biogeography. Numerous zoological examples are presented to argue both dispersalist and vicariance viewpoints. It is proposed that the modern moss flora of the Greater Antilles is best explained primarily by dispersal events. Post-vicariant events, such as Pleistocene climate changes, would have extirpated the vast majority of mosses from the islands and even among those taxa that survived, disperal by the same taxa would have obscured their origins. It is assumed that many of the North American elements in the high elevations of Hispaniola are a result of invasions during the Pleistocene. The Andean elements are considered relatively recent dispersally derived taxa that have successfully colonized the Antilles because of ecologically compatible habitats
