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Diversification within glacial refugia: tempo and mode of evolution of the polytypic fish Barbus sclateri

Authors

  • HUGO F. GANTE,

    1. School of Life Sciences, Arizona State University, Tempe, AZ 85287-4601, USA
    2. Centro de Biologia Ambiental and Museu Bocage – Museu Nacional de História Natural, Rua da Escola Politécnica 58, 1269-102 Lisboa, Portugal
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  • JOANA MICAEL,

    1. Centro de Biologia Ambiental and Museu Bocage – Museu Nacional de História Natural, Rua da Escola Politécnica 58, 1269-102 Lisboa, Portugal
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    • Present address: CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos – Pólo Açores, Departamento de Biologia, Universidade dos Açores, Rua da Mãe de Deus, Apartado 1422, 9501-855 Ponta Delgada, Açores, Portugal

  • FRANCISCO J. OLIVA-PATERNA,

    1. Department of Zoology and Anthropology, University of Murcia, E-30100 Murcia, Spain
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  • IGNACIO DOADRIO,

    1. Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, CSIC, C/José Gutiérrez Abascal, 2, 28006 Madrid, Spain
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  • THOMAS E. DOWLING,

    1. School of Life Sciences, Arizona State University, Tempe, AZ 85287-4601, USA
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  • MARIA JUDITE ALVES

    1. Centro de Biologia Ambiental and Museu Bocage – Museu Nacional de História Natural, Rua da Escola Politécnica 58, 1269-102 Lisboa, Portugal
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Hugo F. Gante, Fax: +357213969784; E-mail: hugo.gante@asu.edu

Abstract

A diversity of evolutionary processes can be responsible for generating and maintaining biodiversity. Molecular markers were used to investigate the influence of Plio-Pleistocene climatic oscillations on the evolutionary history of taxa restricted to the freshwaters of a classical glacial refugium. Population genetic, phylogenetic and phylogeographical methods allowed the inference of temporal dynamics of cladogenesis and processes shaping present-day genetic constitution of Barbus sclateri, a polytypic taxon found in several independent river drainages in southern Iberian Peninsula. Results from different analyses consistently indicate several range expansions, high levels of allopatric fragmentation, and admixture following secondary contacts throughout its evolutionary history. Using a Bayesian demographical coalescent model on mitochondrial DNA sequences calibrated with fossil evidence, all cladogenetic events within B. sclateri are inferred to have occurred during the Pleistocene and were probably driven by environmental factors. Our results suggest that glaciation cycles did not inhibit cladogenesis and probably interacted with regional geomorphology to promote diversification. We conclude that this polytypic taxon is a species complex that recently diversified in allopatry, and that Pleistocene glaciation–deglaciation cycles probably contributed to the generation of biological diversity in a classical glacial refugium with high endemicity.

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