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John C Avise - One of the best experts on this subject based on the ideXlab platform.
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phylogeographic histories of representative herpetofauna of the southwestern u s mitochondrial dna variation in the desert iguana dipsosaurus dorsalis and the chuckwalla Sauromalus obesus
Journal of Evolutionary Biology, 1992Co-Authors: Trip Lamb, Thomas R Jones, John C AviseAbstract:To determine whether genetic variation in representative reptiles of the southwestern U.S. may have been similarly molded by the geologic history of the lower Colorado River, we examined restriction site polymorphisms in the mitochondrial DNA (mtDNA) of desert iguanas (Dipsosaurus dorsalis) and chuckwallas (Saurom&s ohesus). Observed phylogeographic structure in these lizards was compared to that reported for the desert tortoise (Xerobates ugassizi), whose mtDNA phylogeny demonstrates a striking genetic break at the Colorado River. Both the desert iguana and chuckwalla exhibit extensive mtDNA polymorphism, with respective genotypic diversities G = 0.963 and 0.983, close to the maximum possible value of 1.0. Individual mtDNA clones, as well as clonal assemblages defined by specific levels of genetic divergence, showed pronounced geographic localization. Nonetheless, for each species the distributions of certain clones and most major clonal groupings encompass both sides of the Colorado River valley, and hence are clearly incongruent with the phylogeographic pattern of the desert tortoise. Overall, available molecular evidence provides no indication that the intraspecific phylogenies of the southwestern U.S. herpetofauna have been concordantly shaped by a singular vicariant factor of overriding significance.
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Phylogeographic histories of representative herpetofauna of the southwestern U.S.: mitochondrial DNA variation in the desert iguana (Dipsosaurus dorsalis) and the chuckwalla (Sauromalus obesus)
eScholarship University of California, 1992Co-Authors: Lamb T, Tr Jones, John C AviseAbstract:To determine whether genetic variation in representative reptiles of the southwestern U.S. may have been similarly molded by the geologic history of the lower Colorado River, we examined restriction site polymorphisms in the mitochondrial DNA (mtDNA) of desert iguanas (Dipsosaurus dorsalis) and chuckwallas (Sauromalus obesus). Observed phylogeographic structure in these lizards was compared to that reported for the desert tortoise (Xerobates agassizi), whose mtDNA phylogeny demonstrates a striking genetic break at the Colorado River. Both the desert iguana and chuckwalla exhibit extensive mtDNA polymorphism, with respective genotypic diversities G = 0.963 and 0.983, close to the maximum possible value of 1.0. Individual mtDNA clones, as well as clonal assemblages defined by specific levels of genetic divergence, showed pronounced geographic localization. Nonetheless, for each species the distributions of certain clones and most major clonal groupings encompass both sides of the Colorado River valley, and hence are clearly incongruent with the phylogeographic pattern of the desert tortoise. Overall, available molecular evidence provides no indication that the intraspecific phylogenies of the southwestern U.S. herpetofauna have been concordantly shaped by a singular vicariant factor of overriding significance. Copyright © 1992, Wiley Blackwell. All rights reserve
Bradford D Hollingsworth - One of the best experts on this subject based on the ideXlab platform.
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war of the iguanas conflicting molecular and morphological phylogenies and long branch attraction in iguanid lizards
Systematic Biology, 2000Co-Authors: John J Wiens, Bradford D HollingsworthAbstract:Recent studies based on different types of data (i.e., morphology, molecules) have found strongly conflicting phylogenies for the genera of iguanid lizards but have been unable to explain the basis for this incongruence. We reanalyze published data from morphology and from the mito- chondrial ND4, cytochrome b, 12S, and 16S genes to explore the sources of incongruence and re- solve these conflicts. Much of the incongruence centers on the genus Cyclura, which is the sister taxon of Iguana, according to parsimony analyses of the morphology and the ribosomal genes, but is the sister taxon of all other Iguanini, according to the protein-coding genes. Maximum likelihood analyses show that there has been an increase in the rate of nucleotide substitution in Cyclura in the two protein-coding genes (ND4 and cytochrome b), although this increase is not as clear when par- simony is used to estimate branch lengths. Parametric simulations suggest that Cyclura may be mis- placed by the protein-coding genes as a result of long-branch attraction; even when Cyclura and Iguana are sister taxa in a simulated phylogeny, Cyclura is still placed as the basal member of the Iguanini by parsimony analysis in 55% of the replicates. A similar long-branch attraction problem may also exist in the morphological data with regard to the placement of Sauromalus with the Gala - pagos iguanas ( Amblyrhynchus and Conolophus). The results have many implications for the analysis of diverse data sets, the impact of long branches on parsimony and likelihood methods, and the use of certain protein-coding genes in phylogeny reconstruction. (Data set incongruence; Iguanidae; likelihood; long-branch attraction, parsimony.)
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War of the iguanas: Conflicting molecular and morphological phylogenies and long-branch attraction in iguanid lizards. Syst. Biol
2000Co-Authors: John J Wiens, Bradford D HollingsworthAbstract:Abstract.—Recent studies based on different types of data (i.e., morphology, molecules) have found strongly conflicting phylogenies for the genera of iguanid lizards but have been unable to explain the basis for this incongruence. We reanalyze published data from morphology and from the mito-chondrial ND4, cytochrome b, 12S, and 16S genes to explore the sources of incongruence and re-solve these conflicts. Much of the incongruence centers on the genus Cyclura, which is the sister taxon of Iguana, according to parsimony analyses of the morphology and the ribosomal genes, but is the sister taxon of all other Iguanini, according to the protein-coding genes. Maximum likelihood analyses show that there has been an increase in the rate of nucleotide substitution in Cyclura in the two protein-coding genes (ND4 and cytochrome b), although this increase is not as clear when par-simony is used to estimate branch lengths. Parametric simulations suggest that Cyclura may be mis-placed by the protein-coding genes as a result of long-branch attraction; even when Cyclura and Iguana are sister taxa in a simulated phylogeny, Cyclura is still placed as the basal member of the Iguanini by parsimony analysis in 55 % of the replicates. A similar long-branch attraction problem may also exist in the morphological data with regard to the placement of Sauromalus with the Galá-pagos iguanas (Amblyrhynchus and Conolophus). The results have many implications for the analysi
John J Wiens - One of the best experts on this subject based on the ideXlab platform.
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war of the iguanas conflicting molecular and morphological phylogenies and long branch attraction in iguanid lizards
Systematic Biology, 2000Co-Authors: John J Wiens, Bradford D HollingsworthAbstract:Recent studies based on different types of data (i.e., morphology, molecules) have found strongly conflicting phylogenies for the genera of iguanid lizards but have been unable to explain the basis for this incongruence. We reanalyze published data from morphology and from the mito- chondrial ND4, cytochrome b, 12S, and 16S genes to explore the sources of incongruence and re- solve these conflicts. Much of the incongruence centers on the genus Cyclura, which is the sister taxon of Iguana, according to parsimony analyses of the morphology and the ribosomal genes, but is the sister taxon of all other Iguanini, according to the protein-coding genes. Maximum likelihood analyses show that there has been an increase in the rate of nucleotide substitution in Cyclura in the two protein-coding genes (ND4 and cytochrome b), although this increase is not as clear when par- simony is used to estimate branch lengths. Parametric simulations suggest that Cyclura may be mis- placed by the protein-coding genes as a result of long-branch attraction; even when Cyclura and Iguana are sister taxa in a simulated phylogeny, Cyclura is still placed as the basal member of the Iguanini by parsimony analysis in 55% of the replicates. A similar long-branch attraction problem may also exist in the morphological data with regard to the placement of Sauromalus with the Gala - pagos iguanas ( Amblyrhynchus and Conolophus). The results have many implications for the analysis of diverse data sets, the impact of long branches on parsimony and likelihood methods, and the use of certain protein-coding genes in phylogeny reconstruction. (Data set incongruence; Iguanidae; likelihood; long-branch attraction, parsimony.)
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War of the iguanas: Conflicting molecular and morphological phylogenies and long-branch attraction in iguanid lizards. Syst. Biol
2000Co-Authors: John J Wiens, Bradford D HollingsworthAbstract:Abstract.—Recent studies based on different types of data (i.e., morphology, molecules) have found strongly conflicting phylogenies for the genera of iguanid lizards but have been unable to explain the basis for this incongruence. We reanalyze published data from morphology and from the mito-chondrial ND4, cytochrome b, 12S, and 16S genes to explore the sources of incongruence and re-solve these conflicts. Much of the incongruence centers on the genus Cyclura, which is the sister taxon of Iguana, according to parsimony analyses of the morphology and the ribosomal genes, but is the sister taxon of all other Iguanini, according to the protein-coding genes. Maximum likelihood analyses show that there has been an increase in the rate of nucleotide substitution in Cyclura in the two protein-coding genes (ND4 and cytochrome b), although this increase is not as clear when par-simony is used to estimate branch lengths. Parametric simulations suggest that Cyclura may be mis-placed by the protein-coding genes as a result of long-branch attraction; even when Cyclura and Iguana are sister taxa in a simulated phylogeny, Cyclura is still placed as the basal member of the Iguanini by parsimony analysis in 55 % of the replicates. A similar long-branch attraction problem may also exist in the morphological data with regard to the placement of Sauromalus with the Galá-pagos iguanas (Amblyrhynchus and Conolophus). The results have many implications for the analysi
Trip Lamb - One of the best experts on this subject based on the ideXlab platform.
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phylogeographic histories of representative herpetofauna of the southwestern u s mitochondrial dna variation in the desert iguana dipsosaurus dorsalis and the chuckwalla Sauromalus obesus
Journal of Evolutionary Biology, 1992Co-Authors: Trip Lamb, Thomas R Jones, John C AviseAbstract:To determine whether genetic variation in representative reptiles of the southwestern U.S. may have been similarly molded by the geologic history of the lower Colorado River, we examined restriction site polymorphisms in the mitochondrial DNA (mtDNA) of desert iguanas (Dipsosaurus dorsalis) and chuckwallas (Saurom&s ohesus). Observed phylogeographic structure in these lizards was compared to that reported for the desert tortoise (Xerobates ugassizi), whose mtDNA phylogeny demonstrates a striking genetic break at the Colorado River. Both the desert iguana and chuckwalla exhibit extensive mtDNA polymorphism, with respective genotypic diversities G = 0.963 and 0.983, close to the maximum possible value of 1.0. Individual mtDNA clones, as well as clonal assemblages defined by specific levels of genetic divergence, showed pronounced geographic localization. Nonetheless, for each species the distributions of certain clones and most major clonal groupings encompass both sides of the Colorado River valley, and hence are clearly incongruent with the phylogeographic pattern of the desert tortoise. Overall, available molecular evidence provides no indication that the intraspecific phylogenies of the southwestern U.S. herpetofauna have been concordantly shaped by a singular vicariant factor of overriding significance.
Thomas R Jones - One of the best experts on this subject based on the ideXlab platform.
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phylogeographic histories of representative herpetofauna of the southwestern u s mitochondrial dna variation in the desert iguana dipsosaurus dorsalis and the chuckwalla Sauromalus obesus
Journal of Evolutionary Biology, 1992Co-Authors: Trip Lamb, Thomas R Jones, John C AviseAbstract:To determine whether genetic variation in representative reptiles of the southwestern U.S. may have been similarly molded by the geologic history of the lower Colorado River, we examined restriction site polymorphisms in the mitochondrial DNA (mtDNA) of desert iguanas (Dipsosaurus dorsalis) and chuckwallas (Saurom&s ohesus). Observed phylogeographic structure in these lizards was compared to that reported for the desert tortoise (Xerobates ugassizi), whose mtDNA phylogeny demonstrates a striking genetic break at the Colorado River. Both the desert iguana and chuckwalla exhibit extensive mtDNA polymorphism, with respective genotypic diversities G = 0.963 and 0.983, close to the maximum possible value of 1.0. Individual mtDNA clones, as well as clonal assemblages defined by specific levels of genetic divergence, showed pronounced geographic localization. Nonetheless, for each species the distributions of certain clones and most major clonal groupings encompass both sides of the Colorado River valley, and hence are clearly incongruent with the phylogeographic pattern of the desert tortoise. Overall, available molecular evidence provides no indication that the intraspecific phylogenies of the southwestern U.S. herpetofauna have been concordantly shaped by a singular vicariant factor of overriding significance.
