Divergent evolutionary processes associated with colonization of offshore islands

• Published in: Molecular Ecology
• Main Authors: Martinkova, Natalia, Barnett, Ross, Cucchi, Thomas, Struchen, Rahel, Pascal, Michel, Fischer, Martin C, Higham, Thomas, Brace, Selina, Ho, Simon Y.W., Quere, Jean-Pierre, Higgins, Paul O', Excoffier, Laurent, Heckel, Gerald, Hoelzel, A. Rus, Dobney, Keith M., Searle, Jeremy B.
• Other Authors: University of York York, UK, Czech Academy of Sciences Prague (CAS), Sch Biol & Biomed Sci, Durham University, University of Aberdeen, University of Bern, Écologie et santé des écosystèmes (ESE), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Swiss Inst Bioinformat, Oxford Radiocarbon Accelerator Unit, RLAHA, Egham TW20 0EX, Middlesex University, NSW 2006, The University of Sydney, Centre de Biologie pour la Gestion des Populations (UMR CBGP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut de Recherche pour le Développement (IRD France-Sud )-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), York YO10 5DD, Weill Medical College of Cornell University New York, Marie Curie Intra European Fellowship; Swiss National Science Foundation 31003A-127377, 3100A0-112072, 3100-126074, European Community 226506-CP-CSA-Infra, Wellcome Trust University GR071037, Arts and Humanities Research Council 119396
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: demographic analysis; genetic replacement; island colonization; Microtus arvalis; phylogeography; vole microtus-arvalis; common vole; mitochondrial-dna; population-growth; phylogenetic analyses; mainland populations; molecular phylogeny; statistical tests; genetic diversity; late-pleistocene; genetics; lattre p; agriculture ecosystems & environment; [SDV]Life Sciences [q-bio]; Ark the; Common vole
• Online Access: https://hal.archives-ouvertes.fr/hal-01210192; https://hal.archives-ouvertes.fr/hal-01210192/document; https://hal.archives-ouvertes.fr/hal-01210192/file/Martinkova_etal_2013_Divergent_evolutionary_1.pdf; https://doi.org/10.1111/mec.12462

Oceanic islands have been a test ground for evolutionary theory, but here, we focus on the possibilities for evolutionary study created by offshore islands. These can be colonized through various means and by a wide range of species, including those with low dispersal capabilities. We use morphology, modern and ancient sequences of cytochrome b (cytb) and microsatellite genotypes to examine colonization history and evolutionary change associated with occupation of the Orkney archipelago by the common vole (Microtus arvalis), a species found in continental Europe but not in Britain. Among possible colonization scenarios, our results are most consistent with human introduction at least 5100bp (confirmed by radiocarbon dating). We used approximate Bayesian computation of population history to infer the coast of Belgium as the possible source and estimated the evolutionary timescale using a Bayesian coalescent approach. We showed substantial morphological divergence of the island populations, including a size increase presumably driven by selection and reduced microsatellite variation likely reflecting founder events and genetic drift. More surprisingly, our results suggest that a recent and widespread cytb replacement event in the continental source area purged cytb variation there, whereas the ancestral diversity is largely retained in the colonized islands as a genetic ark'. The replacement event in the continental M.arvalis was probably triggered by anthropogenic causes (land-use change). Our studies illustrate that small offshore islands can act as field laboratories for studying various evolutionary processes over relatively short timescales, informing about the mainland source area as well as the island.