Peoecological evidence ofRaphiain the Pre-Columbian Neotropics

Abstract

ABSTRACTDisjunctions between Africa and the Neotropics present a puzzle that is key to understanding the biogeography of the diverse floras and faunas of both continents. Many authors have proposed thatRaphia taedigeraMaur., the sole Neotropical representative of an otherwise African genus, has been introduced to the New World. Paleoecological data from a freshwater swamp in Nicaragua, which yieldedR. taedigerapollen dating to 2800 ± 90 y before present (BP) andRaphiaseed fragments from 2040 ± 60 BP are presented. These illustrate thatRaphia taedigeraarrived in the New World before trans-Atlantic trade by humans and thus arrived as a result of a natural phenomenon. The lack of differentiation ofR. taedigerafrom the African sister taxon,R. vinifera, suggests recent separation of the two species (i.e. after the creation of the southern Atlantic Ocean by the splitting of West Gondwana). Other evidence supports dispersal ofRaphiaby ocean currents. The palm probably arrived from Africa by floating as an individual fruit or on a raft of vegetation. Thus,R. taedigerarepresents another example of trans-Atlantic dispersal, strengthening the link between the flora and fauna of Africa and the Neotropics.