Kleist, Annabelle C. , Nelson, Christine L. , Geiger, Jennifer M. O. , Korall, Petra , Ranker, Tom A. , Pryer, Kathleen M. .
Alternate pathways of fern dispersal to the Hawaiian Islands, Part 3: Cibotium.
THE Hawaiian Islands are the most isolated large group of islands on Earth, yet they are home to nearly 200 species of native ferns and lycophytes. Although species endemism is high (80%), there seems to have been little autochthonous speciation, as Hawaiian fern lineages are generally species-poor. Thus, the probable number of successful colonizations of fern species to the islands compared to the number of extant species is relatively high compared to flowering plants, which generally are represented by more species-rich lineages. Because fern spores are most likely dispersed through the air via the wind, weather and climate patterns are undoubtedly important factors determining the geographical origins of the ancestors of Hawaiian ferns. We are conducting molecular biogeographical studies of multiple groups of Hawaiian ferns to ascertain the likely geographical origin of each group and to explore the nature of shared pathways of dispersal across unrelated taxa. The tree fern genus Cibotium (Dicksoniaceae) is represented in the Hawaiian Islands by four endemic species: C. nealiae, C. chamissoi, C. menziesii, and C. glaucum. The genus comprises approximately ten species worldwide. Comparative cpDNA sequence data support the endemic Hawaiian Cibotium species as monophyletic and thus we hypothesize that the diversity of Cibotium in Hawaii is due to speciation following the colonization of the Islands by the ancestor of this clade. Our results are consistent with the hypothesis that the ancestor of the Hawaiian Cibotium species dispersed from the Neotropics, possibly via the tradewinds or a storm.
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1 - Caroll College, Department of Natural Science, 1601 North Benton Ave., Helena, Montana, 59625, USA
2 - Duke University, Department of Biology, 139 Biological Sciences Building, PO Box 90338, Durham, North Carolina, 27708, USA, Department of Phanerogamic Botany, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden,
3 - University of Colorado, University Museum & Department of Ecology and Evolutionary Biology, 265 UCB, Boulder, Colorado, 80309, USA
4 - Duke University, Department of Biology, 139 Biological Sciences Building, PO Box 90338, Durham, North Carolina, 27708, USA
Presentation Type: Oral Paper:Papers for Sections
Date: Monday, July 31st, 2006
Time: 2:15 PM