Molecular phylogenetics and biogeography of galaxiid fishes (Osteichthyes: Galaxiidae): dispersal, vicariance, and the position of Lepidogalaxias salamandroides.
TLDR
The species-rich genus Galaxias is shown to be polyphyletic and the generic taxonomy of the Galaxiinae is reassessed in the light of phylogenetic relationships, and the loss of this migratory phase may be a major cause of speciation.Abstract:
The galaxiid fishes exhibit a gondwanan distribution. We use mitochondrial DNA sequences to test conflicting vicariant and dispersal biogeographic hypotheses regarding the Southern Hemisphere range of this freshwater group. Although phylogenetic resolution of cytochrome b and 16S rRNA sequences is largely limited to more recent divergences, our data indicate that the radiation can be interpreted as several relatively recent dispersal events superimposed on an ancient gondwanan radiation. Genetic relationships contradict the findings of recent morphological analyses of galaxioid fishes. In particular, we examine several hypotheses regarding phylogenetic placement of the enigmatic Lepidogalaxias. Although most workers consider Lepidogalaxias to be an unusual scaled member of the Southern Hemisphere galaxioids, it has also been suggested that this species is related to the Northern Hemisphere esocoids. Our data strongly suggest that this species is not a galaxiid, and the alternative hypothesized esocoid relationship cannot be rejected. The species-rich genus Galaxias is shown to be polyphyletic and the generic taxonomy of the Galaxiinae is reassessed in the light of phylogenetic relationships. Juvenile saltwater-tolerance is phylogenetically distributed throughout the Galaxiinae, and the loss of this migratory phase may be a major cause of speciation.read more
Citations
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Extreme positive selection on a new highly-expressed larval glycoprotein (LGP) gene in Galaxias fishes (Osmeriformes: Galaxiidae)
Lise J. Wallis,Graham P. Wallis +1 more
TL;DR: It is postulate that the strong Darwinian evolution exhibited by this protein may reflect some type of immunoprotection at this vulnerable larval stage and argue clearly against the possibility of a pseudogene.
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Historical and Contemporary Diversity of Galaxiids in South America: Biogeographic and Phylogenetic Perspectives
TL;DR: Galaxiid fishes from South America are represented by three genera (Aplochiton, Brachygalaxias and Galaxias) and eight species as discussed by the authors, and their genetic patterns have been studied over the last two decades to disentangle how historical and contemporary processes influenced their biogeographic distribution and phylogeographic patterns.
References
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Journal ArticleDOI
Clustal w: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice
TL;DR: The sensitivity of the commonly used progressive multiple sequence alignment method has been greatly improved and modifications are incorporated into a new program, CLUSTAL W, which is freely available.
Journal ArticleDOI
Confidence limits on phylogenies: an approach using the bootstrap.
TL;DR: The recently‐developed statistical method known as the “bootstrap” can be used to place confidence intervals on phylogenies and shows significant evidence for a group if it is defined by three or more characters.
Journal ArticleDOI
A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences.
TL;DR: Some examples were worked out using reported globin sequences to show that synonymous substitutions occur at much higher rates than amino acid-altering substitutions in evolution.
Journal ArticleDOI
Evolutionary trees from DNA sequences: A maximum likelihood approach
TL;DR: A computationally feasible method for finding such maximum likelihood estimates is developed, and a computer program is available that allows the testing of hypotheses about the constancy of evolutionary rates by likelihood ratio tests.