Molecular systematics and phylogeography of the dusky dolphin (Lagenorhynchus obscurus) derived from nuclear and mitochondrial loci
This study presents evidence from mitochondrial and nuclear loci that there is genetic divergence among and within geographic populations of Lagenorhynchus obscurus. The effect of seasonal variation on the genetic structure within New Zealand was examined with mitochondrial DNA control region sequen...
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Texas A&M University
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fttexasamuniv:oai:repository.tamu.edu:1969.1/3186 2023-05-15T17:36:21+02:00 Molecular systematics and phylogeography of the dusky dolphin (Lagenorhynchus obscurus) derived from nuclear and mitochondrial loci Wursig, Bernd Honeycutt, Rodney L. Woolley, Jim Fitzgerald, Lee 2006-04-12T16:04:05Z http://hdl.handle.net/1969.1/3186 en_US eng Texas A&M University http://hdl.handle.net/1969.1/3186 nuclear gene phylogeography dolphin systematics data interaction population structure dusky dolphin Lagenorhynchus obscurus west-wind drift Book Thesis 2006 fttexasamuniv 2014-03-30T08:48:46Z This study presents evidence from mitochondrial and nuclear loci that there is genetic divergence among and within geographic populations of Lagenorhynchus obscurus. The effect of seasonal variation on the genetic structure within New Zealand was examined with mitochondrial DNA control region sequences from 4 localities. Analysis of nested haplotype clades indicated genetic fragmentation and at least 1 historical population expansion within New Zealand. AMOVA and Fst values from nuclear and mitochondrial DNA sequences suggested significant divergence between New Zealand, South Africa, Argentina, and Peru. Dispersal via the west-wind drift was not supported by patterns of population structure among regions. Alternatively, these data support reciprocal exchange among all four regions with 100% posterior probability for a root of origin in the Indian/Atlantic Oceans. The degree of divergence between Peru and other regions indicates the isolation of Peruvian stock is temporally correlated with the constriction of Drake??s passage in the Plio-Pleistocene. There is evidence that the Plio-Pliestocene paleoceanography of the Indian and Southern Atlantic Oceans influenced phylogeography with shifts of temperate sea surface temperatures northward ~5?? of latitude, disrupting the dispersal corridor between New Zealand and Atlantic populations. A preference for temperate waters along continental shelves is proposed as an explanation for lack of contemporary genetic exchange among regions. This study supports the polyphyly of the genus Lagenorhynchus. North Atlantic species form a monophyletic Lagenorhynchus. In the Southern Hemisphere, L. australis/L. cruciger and L. obliquidens/L. obscurus do not form a monophyletic group. I discuss the taxonomic implications and propose taxonomic revision of the genus based on these results. Measures of character interaction indicate that combined evidence from nuclear and mitochondrial genes provide better phylogenetic resolution among delphinid lineages than any data partition independently, despite some indications of conflict among mitochondrial and nuclear data. Book North Atlantic Texas A&M University Digital Repository Indian New Zealand Argentina |
institution |
Open Polar |
collection |
Texas A&M University Digital Repository |
op_collection_id |
fttexasamuniv |
language |
English |
topic |
nuclear gene phylogeography dolphin systematics data interaction population structure dusky dolphin Lagenorhynchus obscurus west-wind drift |
spellingShingle |
nuclear gene phylogeography dolphin systematics data interaction population structure dusky dolphin Lagenorhynchus obscurus west-wind drift Molecular systematics and phylogeography of the dusky dolphin (Lagenorhynchus obscurus) derived from nuclear and mitochondrial loci |
topic_facet |
nuclear gene phylogeography dolphin systematics data interaction population structure dusky dolphin Lagenorhynchus obscurus west-wind drift |
description |
This study presents evidence from mitochondrial and nuclear loci that there is genetic divergence among and within geographic populations of Lagenorhynchus obscurus. The effect of seasonal variation on the genetic structure within New Zealand was examined with mitochondrial DNA control region sequences from 4 localities. Analysis of nested haplotype clades indicated genetic fragmentation and at least 1 historical population expansion within New Zealand. AMOVA and Fst values from nuclear and mitochondrial DNA sequences suggested significant divergence between New Zealand, South Africa, Argentina, and Peru. Dispersal via the west-wind drift was not supported by patterns of population structure among regions. Alternatively, these data support reciprocal exchange among all four regions with 100% posterior probability for a root of origin in the Indian/Atlantic Oceans. The degree of divergence between Peru and other regions indicates the isolation of Peruvian stock is temporally correlated with the constriction of Drake??s passage in the Plio-Pleistocene. There is evidence that the Plio-Pliestocene paleoceanography of the Indian and Southern Atlantic Oceans influenced phylogeography with shifts of temperate sea surface temperatures northward ~5?? of latitude, disrupting the dispersal corridor between New Zealand and Atlantic populations. A preference for temperate waters along continental shelves is proposed as an explanation for lack of contemporary genetic exchange among regions. This study supports the polyphyly of the genus Lagenorhynchus. North Atlantic species form a monophyletic Lagenorhynchus. In the Southern Hemisphere, L. australis/L. cruciger and L. obliquidens/L. obscurus do not form a monophyletic group. I discuss the taxonomic implications and propose taxonomic revision of the genus based on these results. Measures of character interaction indicate that combined evidence from nuclear and mitochondrial genes provide better phylogenetic resolution among delphinid lineages than any data partition independently, despite some indications of conflict among mitochondrial and nuclear data. |
author2 |
Wursig, Bernd Honeycutt, Rodney L. Woolley, Jim Fitzgerald, Lee |
format |
Book |
title |
Molecular systematics and phylogeography of the dusky dolphin (Lagenorhynchus obscurus) derived from nuclear and mitochondrial loci |
title_short |
Molecular systematics and phylogeography of the dusky dolphin (Lagenorhynchus obscurus) derived from nuclear and mitochondrial loci |
title_full |
Molecular systematics and phylogeography of the dusky dolphin (Lagenorhynchus obscurus) derived from nuclear and mitochondrial loci |
title_fullStr |
Molecular systematics and phylogeography of the dusky dolphin (Lagenorhynchus obscurus) derived from nuclear and mitochondrial loci |
title_full_unstemmed |
Molecular systematics and phylogeography of the dusky dolphin (Lagenorhynchus obscurus) derived from nuclear and mitochondrial loci |
title_sort |
molecular systematics and phylogeography of the dusky dolphin (lagenorhynchus obscurus) derived from nuclear and mitochondrial loci |
publisher |
Texas A&M University |
publishDate |
2006 |
url |
http://hdl.handle.net/1969.1/3186 |
geographic |
Indian New Zealand Argentina |
geographic_facet |
Indian New Zealand Argentina |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://hdl.handle.net/1969.1/3186 |
_version_ |
1766135817332326400 |