ibclogo XVI International Botanical Congess


Abstract Number: 4283
Session = 19.7.6


HOMOLOGIES IN GAMETOPHYTE STRUCTUR


E. D. R. Farrar, C. L. Dassler and W-L. Chiou, Department of Botany, Iowa State University, Illinois Natural History Survey, Taiwan Forestry Research Institute


Use of morphological characters in phylogenetic reconstruction has two goals: 1) to improve the resolution and accuracy of the reconstruction, and 2) to promote understanding of character evolution. Relative success in these goals is dependent upon correct interpretation of the homology of character states. Pryer et al. (1995) evaluated 22 morphological characters of the gametophyte generation of ferns for potential use in phylogenetic reconstruction. One-half of these characters were judged unusable because of inadequate information or because they were clearly linked with one of the 11 characters used. We examine these and other characters relative to the probable homology of similar morphological states across taxa. Particular emphasis is given to characters of growth form, including gemma, that show a strong correlation with habitat type and are thus probably not homologous between families. Evidence of non- homology of other similar morphological expressions such as multicellular hairs is recognizable in lineage-specific differences in developmental origins of these structures.


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