Motley, Timothy J. , Dempewolf, Hannes , Lorence, David H , Wagner, Warren .
Biogeographic Patterns and Affinities of the Pacific Genera Oparanthus and Fitchia (Coreopsideae: Asteraceae).
Southeast Polynesia (French Polynesia and Cook Islands) is a remote area, 3000 km away from the nearest continental landmass. The high islands are of relatively young geological age (1 – 7 mya). Oparanthus is a genus endemic to French Polynesia (Marquesas Archipelago and Rapa) and is sister to Fitchia which is endemic to SE Polynesia (Cook Islands, Society Islands, and Rapa). These two genera with no obvious affinities to other Pacific Asteraceae are an interesting case for the study of island biogeography. This study is a species-level phylogenetic analysis of Oparanthus and Fitchia using quickly evolving gene regions (ITS, ETS, and 5S-NTS) from the nuclear ribosomal genome. Our goals were to test the migration hypotheses for Oparanthus and Fitchia among islands of the Southeastern Pacific and to investigate the biogeographic affinities of this Pacific lineage to other members of the Coreopsideae. Recent molecular studies of the Coreopsideae placed the genera sister Caribbean genera (Selleophytum and Narvalina), and we confirm this finding. The combined maximum parsimony analysis of the three gene regions resolves Fitchia and Oparanthus clearly as sister taxa. Rapa, though more distant from the Caribbean islands, was most likely the area of origin. Subsequent long distance dispersal allowed the colonization and radiation on northern archipelagos of the southeastern Pacific.
Log in to add this item to your schedule
1 - Old Dominion University, Department of Biology, 110 Mills Godwin Building/45th Street, Norfolk, Virginia, 23529-0266, USA
2 - University of British Columbia, Department of Botany, Vancouver, BC, Canada
3 - National Tropical Botanical Garden, 3530 Papalina Road, Kalaheo, Kauai, Hawaii, 96741, USA
4 - Smithsonian Institution, Department of Botany, MRC 166, National Museum Of Natural History, Washington, DC, 20013-7012, USA
Presentation Type: Oral Paper:Papers for Topics
Date: Wednesday, July 30th, 2008
Time: 8:45 AM