INVESTIGADORES
VIDAL RUSSELL Romina
congresos y reuniones científicas
Título:
Diversification of a Gondwanan mistletoe family: Loranthaceae
Autor/es:
VIDAL-RUSSELL, R.; NICKRENT, D. L.
Lugar:
Bariloche, Rio Negro, Argentina
Reunión:
Congreso; VI Southern Connection congress; 2010
Resumen:
Loranthaceae is the largest mistletoe family with 73 genera and ca. 900 species. It is distributed mainly in tropical areas worldwide, but members are also found in temperate and Mediterranean biomes in South America, Australia, New Zealand, Asia, Africa and Europe. The objective of this study was to reconstruct the biogeographic history for Loranthaceae using a molecular phylogeny based on five genes. The phylogeny was then reconciled with present day distributions, fossil data, tectonic data and biological factors. Penalized likelihood was used to estimate divergence times using several fossils as time constraints. The distribution of Loranthaceae was divided into seven geographical areas that correspond mainly to the continents and these were optimized on the phylogeny. Ancestral area reconstruction suggests an origin of the family in Gondwana in the late Cretaceous with a probable vicariance event that separated taxa between Australia and South America in the Eocene, a date in agreement with geologic data. Further dispersal events from Australia into New Zealand and Asia and from Asia into Africa are necessary to explain the current distribution of taxa. During the Eocene, Australia achieved complete isolation from Antarctica and the Drake Passage between Antarctica and South America opened, thus changing world climate. According to our molecular dating, these events coincide with the evolution of aerial parasitism and diversification of mistletoes in Loranthaceae.