From Settlers to Subspecies: Genetic Differentiation in Commerson’s Dolphins Between South America and the Kerguelen Islands
Commerson’s dolphins (Cephalorhynchus commersonii) are separated into the subspecies C. c. commersonii, found along southern South America (SA) and the Falkland Islands/Islas Malvinas (FI/IM), and C. c. kerguelenensis, restricted to the subantarctic Kerguelen Islands (KI). Following the dispersal mo...
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Online Access: | https://doi.org/10.3389/fmars.2021.782512 https://doaj.org/article/44514ceb75664b52b77301a1276308fd |
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ftdoajarticles:oai:doaj.org/article:44514ceb75664b52b77301a1276308fd 2023-05-15T17:02:04+02:00 From Settlers to Subspecies: Genetic Differentiation in Commerson’s Dolphins Between South America and the Kerguelen Islands Sebastián Kraft MJosé Pérez-Alvarez Carlos Olavarría Rodrigo Moraga C. Scott Baker Debbie Steel Paul Tixier Christophe Guinet Amelia Viricel Paul Brickle Marina Costa Enrique Crespo Cristian Durante Rocio Loizaga Elie Poulin 2021-12-01T00:00:00Z https://doi.org/10.3389/fmars.2021.782512 https://doaj.org/article/44514ceb75664b52b77301a1276308fd EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmars.2021.782512/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2021.782512 https://doaj.org/article/44514ceb75664b52b77301a1276308fd Frontiers in Marine Science, Vol 8 (2021) Cephalorhynchus commersonii colonization divergence last glacial maximum mitochondrial DNA phylogeography Science Q General. Including nature conservation geographical distribution QH1-199.5 article 2021 ftdoajarticles https://doi.org/10.3389/fmars.2021.782512 2022-12-31T04:50:27Z Commerson’s dolphins (Cephalorhynchus commersonii) are separated into the subspecies C. c. commersonii, found along southern South America (SA) and the Falkland Islands/Islas Malvinas (FI/IM), and C. c. kerguelenensis, restricted to the subantarctic Kerguelen Islands (KI). Following the dispersal model proposed for the genus, the latter is thought to have originated from SA after a long-distance dispersal event. To evaluate this biogeographic scenario, a distribution-wide, balanced sampling of mitochondrial DNA (mtDNA) control region sequences was designed. New tissue samples from southern Chile, Argentina, FI/IM, and KI were added to published sequences from SA and KI, for a total of 256 samples. Genetic diversity indices, genetic and phylogeographic structure, and migration rates were calculated. One haplotype was shared between subspecies, with which all haplotypes of C. c. kerguelenensis formed a distinct group in the haplotype network. A new haplotype for C. c. kerguelenensis is reported. Differentiation in haplotype frequencies was found among localities within the distribution of C. c. commersonii, yet the phylogeographic signal was only statistically significant between subspecies. Coalescent-based historical gene flow estimations indicated migration between the northern and southern portions of the species’ range in SA as well as between SA and the FI/IM, but not between these and the KI. The net nucleotide divergence between dolphins from SA and the FI/IM was lower than the recommended threshold value suggested for delimiting subspecies, unlike that found between C. c. commersonii and C. c. kerguelenensis. The results are consistent with the model of post-glacial colonization of KI by South American C. commersonii, followed by an ongoing divergence process and subspecies status. Thus, C. c. kerguelenensis may represent the most recent diversification step of Cephalorhynchus, where isolation from their source population is driving a process of incipient speciation. Article in Journal/Newspaper Kerguelen Islands Directory of Open Access Journals: DOAJ Articles Kerguelen Kerguelen Islands Argentina Frontiers in Marine Science 8 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Cephalorhynchus commersonii colonization divergence last glacial maximum mitochondrial DNA phylogeography Science Q General. Including nature conservation geographical distribution QH1-199.5 |
spellingShingle |
Cephalorhynchus commersonii colonization divergence last glacial maximum mitochondrial DNA phylogeography Science Q General. Including nature conservation geographical distribution QH1-199.5 Sebastián Kraft MJosé Pérez-Alvarez Carlos Olavarría Rodrigo Moraga C. Scott Baker Debbie Steel Paul Tixier Christophe Guinet Amelia Viricel Paul Brickle Marina Costa Enrique Crespo Cristian Durante Rocio Loizaga Elie Poulin From Settlers to Subspecies: Genetic Differentiation in Commerson’s Dolphins Between South America and the Kerguelen Islands |
topic_facet |
Cephalorhynchus commersonii colonization divergence last glacial maximum mitochondrial DNA phylogeography Science Q General. Including nature conservation geographical distribution QH1-199.5 |
description |
Commerson’s dolphins (Cephalorhynchus commersonii) are separated into the subspecies C. c. commersonii, found along southern South America (SA) and the Falkland Islands/Islas Malvinas (FI/IM), and C. c. kerguelenensis, restricted to the subantarctic Kerguelen Islands (KI). Following the dispersal model proposed for the genus, the latter is thought to have originated from SA after a long-distance dispersal event. To evaluate this biogeographic scenario, a distribution-wide, balanced sampling of mitochondrial DNA (mtDNA) control region sequences was designed. New tissue samples from southern Chile, Argentina, FI/IM, and KI were added to published sequences from SA and KI, for a total of 256 samples. Genetic diversity indices, genetic and phylogeographic structure, and migration rates were calculated. One haplotype was shared between subspecies, with which all haplotypes of C. c. kerguelenensis formed a distinct group in the haplotype network. A new haplotype for C. c. kerguelenensis is reported. Differentiation in haplotype frequencies was found among localities within the distribution of C. c. commersonii, yet the phylogeographic signal was only statistically significant between subspecies. Coalescent-based historical gene flow estimations indicated migration between the northern and southern portions of the species’ range in SA as well as between SA and the FI/IM, but not between these and the KI. The net nucleotide divergence between dolphins from SA and the FI/IM was lower than the recommended threshold value suggested for delimiting subspecies, unlike that found between C. c. commersonii and C. c. kerguelenensis. The results are consistent with the model of post-glacial colonization of KI by South American C. commersonii, followed by an ongoing divergence process and subspecies status. Thus, C. c. kerguelenensis may represent the most recent diversification step of Cephalorhynchus, where isolation from their source population is driving a process of incipient speciation. |
format |
Article in Journal/Newspaper |
author |
Sebastián Kraft MJosé Pérez-Alvarez Carlos Olavarría Rodrigo Moraga C. Scott Baker Debbie Steel Paul Tixier Christophe Guinet Amelia Viricel Paul Brickle Marina Costa Enrique Crespo Cristian Durante Rocio Loizaga Elie Poulin |
author_facet |
Sebastián Kraft MJosé Pérez-Alvarez Carlos Olavarría Rodrigo Moraga C. Scott Baker Debbie Steel Paul Tixier Christophe Guinet Amelia Viricel Paul Brickle Marina Costa Enrique Crespo Cristian Durante Rocio Loizaga Elie Poulin |
author_sort |
Sebastián Kraft |
title |
From Settlers to Subspecies: Genetic Differentiation in Commerson’s Dolphins Between South America and the Kerguelen Islands |
title_short |
From Settlers to Subspecies: Genetic Differentiation in Commerson’s Dolphins Between South America and the Kerguelen Islands |
title_full |
From Settlers to Subspecies: Genetic Differentiation in Commerson’s Dolphins Between South America and the Kerguelen Islands |
title_fullStr |
From Settlers to Subspecies: Genetic Differentiation in Commerson’s Dolphins Between South America and the Kerguelen Islands |
title_full_unstemmed |
From Settlers to Subspecies: Genetic Differentiation in Commerson’s Dolphins Between South America and the Kerguelen Islands |
title_sort |
from settlers to subspecies: genetic differentiation in commerson’s dolphins between south america and the kerguelen islands |
publisher |
Frontiers Media S.A. |
publishDate |
2021 |
url |
https://doi.org/10.3389/fmars.2021.782512 https://doaj.org/article/44514ceb75664b52b77301a1276308fd |
geographic |
Kerguelen Kerguelen Islands Argentina |
geographic_facet |
Kerguelen Kerguelen Islands Argentina |
genre |
Kerguelen Islands |
genre_facet |
Kerguelen Islands |
op_source |
Frontiers in Marine Science, Vol 8 (2021) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmars.2021.782512/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2021.782512 https://doaj.org/article/44514ceb75664b52b77301a1276308fd |
op_doi |
https://doi.org/10.3389/fmars.2021.782512 |
container_title |
Frontiers in Marine Science |
container_volume |
8 |
_version_ |
1766055301290655744 |