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Citation for Study 10258

Citation title: "Phylogeny of the moss class Polytrichopsida (Bryophyta): generic- level structure and an anomalous 18S gene tree.".

This study was previously identified under the legacy study ID S2617 (Status: Published).

Citation

Bell N., & Hyv?nen J. 2010. Phylogeny of the moss class Polytrichopsida (Bryophyta): generic- level structure and an anomalous 18S gene tree. Molecular Phylogenetics and Evolution, .

Authors

• Bell N.
• Hyv?nen J.

Abstract

Analysis of an extensive new molecular dataset for the moss class Polytrichopsida provides convincing support for many traditionally recognized genera and identifies higher-level phylogenetic structure with a strong geographic component. A large apical clade that is most diverse in the northern hemisphere is subtended by a grade of southern temperate and tropical genera, while the earliest diverging lineages have widely separated relictual distributions. However, there is strongly supported topological incongruence between the nuclear 18S rRNA gene tree and the chloroplast and mitochondrial data for the positions of some taxa and notably for the status of Pogonatum. While Pogonatum is unambiguously paraphyletic in the 18S tree, it is well supported as monophyletic by the combined chloroplast and mitochondrial data, this being corroborated by several distinctive morphological synapomorphies and a 51-53 bp deletion in the rps4-trnS spacer. We explore various reticulate historical processes and methodological issues as possible explanations for incongruence, and suggest that either 1) the 18S topology is an artefact created by convergence of substitutions at specific sites due to functional and/or molecular-structural constraints not accounted for by the model, or 2) the incongruence is a product of ancient hybridization events. Under the latter scenario, incongruent topologies for Pogonatum are parsimoniously explained if Polytrichum (including Polytrichastrum sect. Aporotheca) is ultimately descended from a hybridization event involving an extinct maternal taxon derived from the branch ancestral to the combined Pogonatum / Polytrichum s.l. clade, and a paternal taxon belonging to (or ancestral to) the apical Pogonatum group to which the majority of extant species belong. Numerous novel relationships of taxonomic and evolutionary significance are supported. Notably, both Polytrichastrum and Oligotrichum are polyphyletic. While Polytrichastrum sect. Aporotheca is closely related to Polytrichum, other species, including the type, are not. The large majority of Oligotrichum species sampled occur in one of two distantly related clades with predominantly northern and southern hemisphere distributions respectively, implying convergent evolution of this morphology in each of the two temperate zones.

About this resource

• Canonical resource URI: http://purl.org/phylo/treebase/phylows/study/TB2:S10258
• Other versions: Nexus NeXML
• Show BibTeX reference

  		@ARTICLE{TreeBASE2Ref18748,
  	 author = {Neil E.  Bell and Jaakko  Hyv?nen},
  	 title = {Phylogeny of the moss class Polytrichopsida (Bryophyta): generic- level structure and an anomalous 18S gene tree.},
  	 year = {2010},
  	 keywords = {},
  	 doi = {},
  	 url = {},
  	 pmid = {},
  	 journal = {Molecular Phylogenetics and Evolution},
  	 volume = {},
  	 number = {},
  	 pages = {},
  	 abstract = {Analysis of an extensive new molecular dataset for the moss class Polytrichopsida provides convincing support for many traditionally recognized genera and identifies higher-level phylogenetic structure with a strong geographic component. A large apical clade that is most diverse in the northern hemisphere is subtended by a grade of southern temperate and tropical genera, while the earliest diverging lineages have widely separated relictual distributions. However, there is strongly supported topological incongruence between the nuclear 18S rRNA gene tree and the chloroplast and mitochondrial data for the positions of some taxa and notably for the status of Pogonatum. While Pogonatum is unambiguously paraphyletic in the 18S tree, it is well supported as monophyletic by the combined chloroplast and mitochondrial data, this being corroborated by several distinctive morphological synapomorphies and a 51-53 bp deletion in the rps4-trnS spacer. We explore various reticulate historical processes and methodological issues as possible explanations for incongruence, and suggest that either 1) the 18S topology is an artefact created by convergence of substitutions at specific sites due to functional and/or molecular-structural constraints not accounted for by the model, or 2) the incongruence is a product of ancient hybridization events. Under the latter scenario, incongruent topologies for Pogonatum are parsimoniously explained if Polytrichum (including Polytrichastrum sect. Aporotheca) is ultimately descended from a hybridization event involving an extinct maternal taxon derived from the branch ancestral to the combined Pogonatum / Polytrichum s.l. clade, and a paternal taxon belonging to (or ancestral to) the apical Pogonatum group to which the majority of extant species belong. Numerous novel relationships of taxonomic and evolutionary significance are supported. Notably, both Polytrichastrum and Oligotrichum are polyphyletic. While Polytrichastrum sect. Aporotheca is closely related to Polytrichum, other species, including the type, are not. The large majority of Oligotrichum species sampled occur in one of two distantly related clades with predominantly northern and southern hemisphere distributions respectively, implying convergent evolution of this morphology in each of the two temperate zones. }
  }
  		

• Show RIS reference

  		TY  - JOUR
  ID  - 18748
  AU  - Bell,Neil E. 
  AU  - Hyv?nen,Jaakko 
  T1  - Phylogeny of the moss class Polytrichopsida (Bryophyta): generic- level structure and an anomalous 18S gene tree.
  PY  - 2010
  KW  - 
  UR  - 
  N2  - Analysis of an extensive new molecular dataset for the moss class Polytrichopsida provides convincing support for many traditionally recognized genera and identifies higher-level phylogenetic structure with a strong geographic component. A large apical clade that is most diverse in the northern hemisphere is subtended by a grade of southern temperate and tropical genera, while the earliest diverging lineages have widely separated relictual distributions. However, there is strongly supported topological incongruence between the nuclear 18S rRNA gene tree and the chloroplast and mitochondrial data for the positions of some taxa and notably for the status of Pogonatum. While Pogonatum is unambiguously paraphyletic in the 18S tree, it is well supported as monophyletic by the combined chloroplast and mitochondrial data, this being corroborated by several distinctive morphological synapomorphies and a 51-53 bp deletion in the rps4-trnS spacer. We explore various reticulate historical processes and methodological issues as possible explanations for incongruence, and suggest that either 1) the 18S topology is an artefact created by convergence of substitutions at specific sites due to functional and/or molecular-structural constraints not accounted for by the model, or 2) the incongruence is a product of ancient hybridization events. Under the latter scenario, incongruent topologies for Pogonatum are parsimoniously explained if Polytrichum (including Polytrichastrum sect. Aporotheca) is ultimately descended from a hybridization event involving an extinct maternal taxon derived from the branch ancestral to the combined Pogonatum / Polytrichum s.l. clade, and a paternal taxon belonging to (or ancestral to) the apical Pogonatum group to which the majority of extant species belong. Numerous novel relationships of taxonomic and evolutionary significance are supported. Notably, both Polytrichastrum and Oligotrichum are polyphyletic. While Polytrichastrum sect. Aporotheca is closely related to Polytrichum, other species, including the type, are not. The large majority of Oligotrichum species sampled occur in one of two distantly related clades with predominantly northern and southern hemisphere distributions respectively, implying convergent evolution of this morphology in each of the two temperate zones. 
  L3  - 
  JF  - Molecular Phylogenetics and Evolution
  VL  - 
  IS  - 
  ER  -