Phylogeography of Aegean green toads (Bufo viridis subgroup): continental hybrid swarm vs. insular diversification with discovery of a new island endemic.

Détails

Ressource 1Télécharger: BMAEvolBiol.pdf (2944.42 [Ko])
Etat: Serval
Version: Final published version
ID Serval
serval:BIB_EA1087D5FBF0
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Phylogeography of Aegean green toads (Bufo viridis subgroup): continental hybrid swarm vs. insular diversification with discovery of a new island endemic.
Périodique
BMC evolutionary biology
Auteur(s)
Dufresnes C., Lymberakis P., Kornilios P., Savary R., Perrin N., Stöck M.
ISSN
1471-2148 (Electronic)
ISSN-L
1471-2148
Statut éditorial
Publié
Date de publication
02/05/2018
Peer-reviewed
Oui
Volume
18
Numéro
1
Pages
67
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: epublish
Résumé
Debated aspects in speciation research concern the amount of gene flow between incipient species under secondary contact and the modes by which post-zygotic isolation accumulates. Secondary contact zones of allopatric lineages, involving varying levels of divergence, provide natural settings for comparative studies, for which the Aegean (Eastern Mediterranean) geography offers unique scenarios. In Palearctic green toads (Bufo viridis subgroup or Bufotes), Plio-Pleistocene (~ 2.6 Mya) diverged species show a sharp transition without contemporary gene flow, while younger lineages, diverged in the Lower-Pleistocene (~ 1.9 Mya), admix over tens of kilometers. Here, we conducted a fine-scale multilocus phylogeographic analysis of continental and insular green toads from the Aegean, where a third pair of taxa, involving Mid-Pleistocene diverged (~ 1.5 Mya) mitochondrial lineages, earlier tentatively named viridis and variabilis, (co-)occurs.
We discovered a new lineage, endemic to Naxos (Central Cyclades), while coastal islands and Crete feature weak genetic differentiation from the continent. In continental Greece, both lineages, viridis and variabilis, form a hybrid swarm, involving massive mitochondrial and nuclear admixture over hundreds of kilometers, without obvious selection against hybrids.
The genetic signatures of insular Aegean toads appear governed by bathymetry and Quaternary sea level changes, resulting in long-term isolation (Central Cyclades: Naxos) and recent land-bridges (coastal islands). Conversely, Crete has been isolated since the end of the Messinian salinity crisis (5.3 My) and Cretan populations thus likely result from human-mediated colonization, at least since Antiquity, from Peloponnese and Anatolia. Comparisons of green toad hybrid zones support the idea that post-zygotic hybrid incompatibilities accumulate gradually over the genome. In this radiation, only one million years of divergence separate a scenario of complete reproductive isolation, from a secondary contact resulting in near panmixia.
Mots-clé
Animals, Base Sequence, Biodiversity, Bufonidae/classification, Cell Nucleus/genetics, DNA, Mitochondrial/genetics, Gene Flow, Genetic Drift, Genetics, Population, Genome, Greece, Islands, Likelihood Functions, Mitochondria/genetics, Phylogeny, Phylogeography, Reproductive Isolation, Sequence Analysis, DNA
Pubmed
Web of science
Open Access
Oui
Création de la notice
17/05/2018 8:50
Dernière modification de la notice
09/05/2019 2:54
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