SOUTH AMERICAN BIOGEOGRAPHY DISENTANGLED THROUGH PODOCARPUS PHYLOGENY

M. PAULA QUIROGA; M.P. MATHIASEN; IGLESIAS, A.; A. PREMOLI

Punta Arenas

Simposio; VIII Souther Connection Congress; 2016

Universidad de Magallanes

Families of southern origin, such as Podocarpaceae are considered key sources of information in plant geography. The biogeographical relevance of Podocarpaceae relies on the fact that it?s the second largest conifer family distributed in temperate and subtropical latitudes. We hereby built a phylogeny of Podocarpus using molecular characters and new fossil data to elucidate biogeographical history of Podocarpus within South America and with Central America and Africa. Phylogenetic reconstructions may elucidate alternative hypotheses that Podocarpus s.l. originated in the Palaeogene and diversified to reach its  present wide distribution as a consequence of long-distance dispersal, or that it consists of ancient (i.e. Cretaceous) widespread lineages that evolved within Gondwanan continents by vicariance. The estimated minimum age of Podocarpus s.l. was dated in the late Cretaceous?early Paleogene. Lineages within Podocarpus were already present by the Eocene and consisted of three latitudinally controlled clades. Biogeographic patterns of extant Podocarpus within South America are the result of vicariance related to  palaeoclimatic changesand tectonic events. The recent diversification of African and northern South American taxa occurred as aresult of dispersal during the Neogene and suggest a biotic connection at subtropical latitudes.