Abstract Detail

Biogeography

Roncal, Julissa [1], Nieto-Blazquez, Maria Esther [2], Cardona, Agustin [3], Bacon, Christine [4].

Historical biogeography of Caribbean endemic plants: insight from dated phylogenetic trees contributes to paleogeography of the region.

The Caribbean archipelago is the largest and most species rich insular system in the Neotropics, yet the origins of this biodiversity hotspot are poorly understood. Four main hypotheses have been proposed to explain Caribbean diversity: vicariance, GAARlandia landspan, long-distance dispersal, and in situ speciation. Here, we use published dated phylogenetic trees and historical biogeographical inferences of Caribbean endemic plants to test amongst these four hypotheses. We compile the colonization times, in situ speciation, and ancestral areas of Caribbean endemic lineages. We model species richness differences among endemic lineages as a function of their colonization time in the Caribbean, resulting in an estimation of the time-for-speciation effect. Our results show that plants repeatedly colonized the West Indies over the last 60 million years from continental America, especially from central and south America. Plant colonization times do not cluster during the GAARlandia timeframe and most colonization events occurred after its putative subsidence. We did not find a relationship between the number of species in each endemic clade and the estimated time when each colonized the Caribbean (no time-for-speciation effect). Our biogeographical synthesis agrees with the published geological constraints from the Lesser Antilles and Aves Ridge which fail to support an emergent land between the Antilles and south America.

1 - Memorial University Of Newfoundland, Biology, 45 Arctic Avenue, St. John's, NL, A1C 5S7, Canada
2 - Senckenberg Biodiversity and Climate Research Centre, Molecular Ecology Group, Frankfurt am Main, Germany
3 - National University of Colombia, Department of Processes and Energy, Medellin, Colombia
4 - University of Göteborg, Department of Biological and Environmental Sciences, Göteborg, Sweden

Keywords:
colonization
divergence time
endemic flora
GAARlandia
in situ speciation
time-for-speciation
vicariance
West Indies.

Presentation Type: Oral Paper
Number: BIOG I001
Abstract ID:70
Candidate for Awards:None