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Effective Population Size, Gene Flow, and Species Status in a Narrow Endemic Sunflower, Helianthus neglectus, Compared to Its Widespread Sister Species, H. petiolaris

Species delimitation has long been a difficult and controversial process, and different operational criteria often lead to different results. In particular, investigators using phenotypic vs. molecular data to delineate species may recognize different boundaries, especially if morphologically or eco...

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Autores principales: Raduski, Andrew R., Rieseberg, Loren H., Strasburg, Jared L.
Formato: Texto
Lenguaje:English
Publicado: Molecular Diversity Preservation International (MDPI) 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2852850/
https://www.ncbi.nlm.nih.gov/pubmed/20386650
http://dx.doi.org/10.3390/ijms11020492
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author Raduski, Andrew R.
Rieseberg, Loren H.
Strasburg, Jared L.
author_facet Raduski, Andrew R.
Rieseberg, Loren H.
Strasburg, Jared L.
author_sort Raduski, Andrew R.
collection PubMed
description Species delimitation has long been a difficult and controversial process, and different operational criteria often lead to different results. In particular, investigators using phenotypic vs. molecular data to delineate species may recognize different boundaries, especially if morphologically or ecologically differentiated populations have only recently diverged. Here we examine the genetic relationship between the widespread sunflower species Helianthus petiolaris and its narrowly distributed sand dune endemic sister species H. neglectus using sequence data from nine nuclear loci. The two species were initially described as distinct based on a number of minor morphological differences, somewhat different ecological tolerances, and at least one chromosomal rearrangement distinguishing them; but detailed molecular data has not been available until now. We find that, consistent with previous work, H. petiolaris is exceptionally genetically diverse. Surprisingly, H. neglectus harbors very similar levels of genetic diversity (average diversity across loci is actually slightly higher in H. neglectus). It is extremely unlikely that such a geographically restricted species could maintain these levels of genetic variation in isolation. In addition, the two species show very little evidence of any genetic divergence, and estimates of interspecific gene flow are comparable to gene flow estimates among regions within H. petiolaris. These results indicate that H. petiolaris and H. neglectus likely do not represent two distinct, isolated gene pools; H. neglectus is probably more accurately thought of as a geographically restricted, morphologically and ecologically distinct subspecies of H. petiolaris rather than a separate species.
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spelling pubmed-28528502010-04-12 Effective Population Size, Gene Flow, and Species Status in a Narrow Endemic Sunflower, Helianthus neglectus, Compared to Its Widespread Sister Species, H. petiolaris Raduski, Andrew R. Rieseberg, Loren H. Strasburg, Jared L. Int J Mol Sci Article Species delimitation has long been a difficult and controversial process, and different operational criteria often lead to different results. In particular, investigators using phenotypic vs. molecular data to delineate species may recognize different boundaries, especially if morphologically or ecologically differentiated populations have only recently diverged. Here we examine the genetic relationship between the widespread sunflower species Helianthus petiolaris and its narrowly distributed sand dune endemic sister species H. neglectus using sequence data from nine nuclear loci. The two species were initially described as distinct based on a number of minor morphological differences, somewhat different ecological tolerances, and at least one chromosomal rearrangement distinguishing them; but detailed molecular data has not been available until now. We find that, consistent with previous work, H. petiolaris is exceptionally genetically diverse. Surprisingly, H. neglectus harbors very similar levels of genetic diversity (average diversity across loci is actually slightly higher in H. neglectus). It is extremely unlikely that such a geographically restricted species could maintain these levels of genetic variation in isolation. In addition, the two species show very little evidence of any genetic divergence, and estimates of interspecific gene flow are comparable to gene flow estimates among regions within H. petiolaris. These results indicate that H. petiolaris and H. neglectus likely do not represent two distinct, isolated gene pools; H. neglectus is probably more accurately thought of as a geographically restricted, morphologically and ecologically distinct subspecies of H. petiolaris rather than a separate species. Molecular Diversity Preservation International (MDPI) 2010-02-02 /pmc/articles/PMC2852850/ /pubmed/20386650 http://dx.doi.org/10.3390/ijms11020492 Text en © 2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland. http://creativecommons.org/licenses/by/3.0 This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
spellingShingle Article
Raduski, Andrew R.
Rieseberg, Loren H.
Strasburg, Jared L.
Effective Population Size, Gene Flow, and Species Status in a Narrow Endemic Sunflower, Helianthus neglectus, Compared to Its Widespread Sister Species, H. petiolaris
title Effective Population Size, Gene Flow, and Species Status in a Narrow Endemic Sunflower, Helianthus neglectus, Compared to Its Widespread Sister Species, H. petiolaris
title_full Effective Population Size, Gene Flow, and Species Status in a Narrow Endemic Sunflower, Helianthus neglectus, Compared to Its Widespread Sister Species, H. petiolaris
title_fullStr Effective Population Size, Gene Flow, and Species Status in a Narrow Endemic Sunflower, Helianthus neglectus, Compared to Its Widespread Sister Species, H. petiolaris
title_full_unstemmed Effective Population Size, Gene Flow, and Species Status in a Narrow Endemic Sunflower, Helianthus neglectus, Compared to Its Widespread Sister Species, H. petiolaris
title_short Effective Population Size, Gene Flow, and Species Status in a Narrow Endemic Sunflower, Helianthus neglectus, Compared to Its Widespread Sister Species, H. petiolaris
title_sort effective population size, gene flow, and species status in a narrow endemic sunflower, helianthus neglectus, compared to its widespread sister species, h. petiolaris
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2852850/
https://www.ncbi.nlm.nih.gov/pubmed/20386650
http://dx.doi.org/10.3390/ijms11020492
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