Get access

Population history of the Hispaniolan hutia Plagiodontia aedium (Rodentia: Capromyidae): testing the model of ancient differentiation on a geotectonically complex Caribbean island

Authors

  • SELINA BRACE,

    1. School of Biological Sciences, Royal Holloway University of London, Egham TW20 0EX, UK
    Search for more papers by this author
  • IAN BARNES,

    1. School of Biological Sciences, Royal Holloway University of London, Egham TW20 0EX, UK
    Search for more papers by this author
  • ADAM POWELL,

    1. Research Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
    2. UCL Genetics Institute (UGI), University College London, Gower Street, London WC1E 6BT, UK
    Search for more papers by this author
  • REBECCA PEARSON,

    1. Department of Respiratory Medicine, National Heart and Lung Institute, Imperial College London, St Mary’s Campus, London W2 1PG, UK
    Search for more papers by this author
  • LANCE G. WOOLAVER,

    1. Wildlife Preservation Canada, 5420 Highway 6 North, Guelph, ON, Canada N1H 6J2
    Search for more papers by this author
  • MARK G. THOMAS,

    1. Research Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
    2. Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvagen 18D, SE-752 36 Uppsala, Sweden
    Search for more papers by this author
  • SAMUEL T. TURVEY

    1. Institute of Zoology, Zoological Society of London, Regent’s Park, London NW1 4RY, UK
    Search for more papers by this author

Ian Barnes, Fax: +44 1784 414224; E-mail: ian.barnes@rhul.ac.uk

Abstract

Hispaniola is a geotectonically complex island consisting of two palaeo-islands that docked c. 10 Ma, with a further geological boundary subdividing the southern palaeo-island into eastern and western regions. All three regions have been isolated by marine barriers during the late Cenozoic and possess biogeographically distinct terrestrial biotas. However, there is currently little evidence to indicate whether Hispaniolan mammals show distributional patterns reflecting this geotectonic history, as the island’s endemic land mammal fauna is now almost entirely extinct. We obtained samples of Hispaniolan hutia (Plagiodontia aedium), one of the two surviving Hispaniolan land mammal species, through fieldwork and historical museum collections from seven localities distributed across all three of the island’s biogeographic regions. Phylogenetic analysis using mitochondrial DNA (cytochrome b) reveals a pattern of historical allopatric lineage divergence in this species, with the spatial distribution of three distinct hutia lineages biogeographically consistent with the island’s geotectonic history. Coalescent modelling, approximate Bayesian computation and approximate Bayes factor analyses support our phylogenetic inferences, indicating near-complete genetic isolation of these biogeographically separate populations and differing estimates of their effective population sizes. Spatial congruence of hutia lineage divergence is not however matched by temporal congruence with divergences in other Hispaniolan taxa or major events in Hispaniola’s geotectonic history; divergence between northern and southern hutia lineages dates to c. 0.6 Ma, significantly later than the unification of the palaeo-islands. The three allopatric Plagiodontia populations should all be treated as distinct management units for conservation, with particular attention required for the northern population (low haplotype diversity) and the south-western population (high haplotype diversity but highly threatened).

Ancillary