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Full-Text Articles in Life Sciences
Xenopus Laevis As A Model Organism, David C. Cannatella, Rafael O. De Sá
Xenopus Laevis As A Model Organism, David C. Cannatella, Rafael O. De Sá
Biology Faculty Publications
Model organisms are often assumed to be representative of some more inclusive taxon of which the species is a part. This assumption leads to mistaken generalizations about the evolutionary and comparative significance of the data gathered. This paper reviews com? parative and evolutionary studies of Xenopus laevis and its relatives. Phylogenetic analysis of data from DNA sequences and morphology indicate that Xenopus is monophyletic and that Silurana is its sister group. The most basal lineages of Pipidae diverged prior to the breakup of Gondwana. The bizarre morphology of Xenopus is in part due to changes in the mode of meta? …
Ribosomal Dna And The Phylogeny Of Frogs, David M. Hills, Loren K. Ammerman, Michael T. Dixon, Rafael O. De Sá
Ribosomal Dna And The Phylogeny Of Frogs, David M. Hills, Loren K. Ammerman, Michael T. Dixon, Rafael O. De Sá
Biology Faculty Publications
Phylogenetic analysis of 1656 aligned sites in the 28S ribosomal RNA gene of frogs supports some of the recently recognized higher groups of anurans but provides counter-support for others. The 28S rDNA data support the monophyly of the recently recognized Pipanura (me- sobatrachians plus neobatrachians), which in turn indicates paraphyly of archaeobatrachians. Me- sobatrachians (pelobatoids plus pipoids), which are either considered paraphyletic or weakly sup- ported as monophyletic in morphological analyses, also receive support as a monophyletic group from the 28S rDNA data. Hyloidea (=Bufonoidea), which is widely recognized but lacks morphological support, receives some molecular support as being monophyletic. …