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Abstract Detail

Symposia: Emerging Results from Studies of Gymnosperms on the Tree of Life II

Rothwell, Gar W. [1], Campbell, Christopher S. [2], Gernandt, David A. [3], Hermsen, Elizabeth J. [4], Holman, Garth [2], Kelch, Dean [5], Ickert-Bond, Steffi [6], Little, Damon [7], Mapes, Gene [1], Mathews, Sarah [8], Ryberg, Patricia E. [9], Stevenson, Dennis Wm. [10], Stockey, Ruth A. [11], Yang, Yong [12].

The role of morphology in contemporary analyses of seed plant phylogeny.

The role of morphology in the resolution of seed plant phylogeny has been the subject of considerable discussion over the past decade, and there is a growing consensus that morphological characters provide unique insights and are important for testing hypotheses that are generated using other sources of data. Morphological analyses can help resolve deep internal nodes of the spermatophyte tree when extinct taxa are included, and they provide valuable tests of systematic hypotheses that result from the analysis of other characters. We have developed the largest and most comprehensive morphological matrix ever assembled for resolving relationships among seed plants. The analyses utilize 385 morphological characters with 460 apomorphic states to evaluate relationships among 350 core taxa of cycads, ginkgophytes, pinoid and cupressophyte conifers, gnetophytes, and flowering plants. The matrix also includes more than 60 species of extinct plants for which organismal concepts have been developed and that represent all of the known gymnosperm clades. Preliminary results of these analyses support previous studies that root seed plants among progymnosperms and place several grades and clades of “seed ferns” at basal nodes of the tree, highlighting the need for morphological data in phylogenetic analyses. They also reveal the most probable sister group relationships for spermatophyte clades with living representatives among the extinct clades, and provide insights for distinguishing among the various hypotheses for living seed plants inferred from molecular sequence data.

Broader Impacts:

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1 - Ohio University, Department of Environmental & Plant Biology, Porter Hall, Richland Avenue, Athens, Ohio, 45701-2979, USA
2 - University of Maine, School of Biology and Ecology, Orono, ME, 04469-5735, USA
3 - Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, 04510 Distrito Federal, Mexico
4 - Cornell University, Department of Plant Biology, Ithaca, New York, 14853, (USA)
5 - California Department of Food & Agriculture, 3294 Meadowview Road, Sacramento, California, 95832, USA
6 - University of Alaska, Museum of the North Herbarium, 907 Yukon Drive, Fairbanks, AK, 99775, USA
7 - The New York Botanical Garden, Lewis B. and Dorothy Cullman Program for Molecular Systematic Studies, 200th St. & Southern Blvd., Bronx, New York, 10458-5126, USA
8 - Harvard University, Arnold Arboretum, Harvard University Herbaria, 22 Divinity Avenue, Cambridge, MA, 02138, USA
9 - Ohio University, Department of Environmental and Plant Biology, Athens, OH, 45701, USA
10 - New York Botanical Garden, Institute of Systematic Botany, 200Th Street & Southern Boulevard, Bronx, New York, 10458-5126, USA
11 - University of Alberta, Department of Biological Sciences, Biological Sciences Centre, Cw 405, Edmonton, Alberta, T6G 2E9, Canada
12 - Chinese Academy of Sciences, State Key Lab of Systematic and Evolutionary Biology, 20 Nanxincun, Xiangshan, Beijing, 100093, China

gymnosperm phylogeny
seed plant systematics

Presentation Type: Symposium or Colloquium Presentation
Session: SY1
Location: Ballroom C/Convention Center
Date: Monday, August 2nd, 2010
Time: 10:00 AM
Number: SY1005
Abstract ID:505

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