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Extreme intraspecific mitochondrial DNA sequence divergence in Galaxias maculatus (Osteichthys: Galaxiidae), one of the world's most widespread freshwater fish.
- Source :
-
Molecular phylogenetics and evolution [Mol Phylogenet Evol] 1999 Feb; Vol. 11 (1), pp. 1-12. - Publication Year :
- 1999
-
Abstract
- Biogeographic controversies surrounding the widespread freshwater fish, Galaxias maculatus, were addressed with DNA sequence data. Mitochondrial cytochrome b and 16S rRNA sequences were obtained from representatives of six populations of this species. Substantial levels of cytochrome b (maximum 14.6%) and 16S rRNA sequence divergence (maximum 6.0%) were detected between western Pacific (Tasmania-New Zealand) and South American (Chile-Falkland Islands) haplotypes. A considerable level of divergence was also detected between Tasmanian and New Zealand haplotypes (maximum 5.1%) and within and among Chilean and Falkland Island G. maculatus (maximum 3. 8%). The phylogenetic structure of haplotypes conflicts with the accepted pattern of continental fragmentation. Molecular clock calibrations suggest that haplotype divergences postdate the fragmentation of Gondwana. These findings point to marine dispersal rather than ancient vicariance as an explanation for the wide distribution. The phylogenetic structure of South American haplotypes was not consistent with their geographic distribution. We consider factors such as population divergence, population size, dispersal, secondary contact, and philopatry as potential causes of the high level of mtDNA nucleotide diversity in this species.<br /> (Copyright 1999 Academic Press.)
- Subjects :
- Amino Acid Sequence
Animals
Base Sequence
Cytochrome b Group genetics
Evolution, Molecular
Fresh Water
Genetic Variation
Haplotypes
Molecular Sequence Data
New Zealand
Phylogeny
RNA, Ribosomal, 16S genetics
Sequence Homology, Nucleic Acid
South America
Statistics as Topic
DNA, Mitochondrial genetics
Fishes genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1055-7903
- Volume :
- 11
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Molecular phylogenetics and evolution
- Publication Type :
- Academic Journal
- Accession number :
- 10082606
- Full Text :
- https://doi.org/10.1006/mpev.1998.0554