Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-3116
Mol Phylogenet Evol. October 1, 2004; 33 (1): 197-213.

A mitochondrial DNA phylogeny of African clawed frogs: phylogeography and implications for polyploid evolution.

Evans BJ , Kelley DB , Tinsley RC , Melnick DJ , Cannatella DC .


Abstract
The African clawed frogs (Silurana and Xenopus), model organisms for scientific inquiry, are unusual in that allopolyploidization has occurred on multiple occasions, giving rise to tetraploid, octoploid, and dodecaploid species. To better understand their evolution, here we estimate a mitochondrial DNA phylogeny from all described and some undescribed species. We examine the timing and location of diversification, and test hypotheses concerning the frequency of polyploid speciation and taxonomy. Using a relaxed molecular clock, we estimate that extant clawed frog lineages originated well after the breakup of Gondwana, about 63.7 million years ago, with a 95% confidence interval from 50.4 to 81.3 million years ago. Silurana and two major lineages of Xenopus have overlapping distributions in sub-Saharan Africa, and dispersal-vicariance analysis suggests that clawed frogs originated in central and/or eastern equatorial Africa. Most or all extant species originated before the Pleistocene; recent rainforest refugia probably acted as "lifeboats" that preserved existing species, rather than "species pumps" where many new successful lineages originated. We estimate that polyploidization occurred at least six times in clawed frogs.

PubMed ID: 15324848
Article link: Mol Phylogenet Evol.
Grant support: NS23684 NINDS NIH HHS

Genes referenced: clock



My Xenbase: [ Log-in / Register ]
version: [4.5.0]

Major funding for Xenbase is provided by the National Institute of Child Health and Human Development, grant P41 HD064556