Paraphyly and multiple causes of phylogenetic incongruence in the moss genus Plagiomnium (Mniaceae)
Abstract:The identification and evaluation of phylogenetic incongruence remains a difficult problem in the reconstruction of evolutionary history. In this study, molecular sequence data were used to reconstruct the phylogeny of the moss genus Plagiomnium (Mniaceae). Separate analyses of gene regions from the nuclear and chloroplast compartments revealed several cases of topological incongruence, which were subsequently evaluated and compared with the behavior of documented allopolyploids in Plagiomnium. Plagiomnium, as currently circumscribed, is paraphyletic, with the epiphytic and primarily Southeast Asian genus Orthomnion nested within Plagiomnium sect. Rostrata. Previously recognized sections of Plagiomnium are also paraphyletic. Eleven out of sixteen species with multiple representatives in the analysis were found to have phylogenetic structure below the currently recognized species level. Populations of P. cuspidatum in Southeastern U.S.A., populations resembling P. tezukae in Southwest China, and three specimens from East Asia that resemble P. maximoviczii all represent distinct evolutionary lineages that may warrant formal taxonomic recognition. Incongruence between the nuclear and chloroplast genomic compartments can be partly explained by the allopolyploid origin of P. medium and P. cuspidatum. However, examples of incongruence in the placement of P. japonicum, P. undulatum, P. venustum, and Orthomnion are probably caused by increased rates of evolution and/or lack of support for branches that include these taxa. These results emphasize the importance of distinguishing between different types of incongruence on a case-by-case basis, before attempting to make general conclusions about the evolutionary processes involved in the creation of discordant gene trees.
Document Type: Research Article
Affiliations: University Herbarium, and Department of Integrative Biology, 1001 Valley Life Sciences Building, University of California – Berkeley, Berkeley, California 94720-2465, U.S.A.
Publication date: 2008-05-01
Impact Factor (2015): 2.9
Taxon electronic back issues (1950-2001) have been released in 2005
Submission of manuscripts: www.editorialmanager.com/taxon
- Information for Authors
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- Regnum Vegetabile
- Taxonomic Literature online
- Taxon electronic back issues (1950-2001) hosted by JSTOR
- Ingenta Connect is not responsible for the content or availability of external websites