Get access

Divergence with gene flow and fine-scale phylogeographical structure in the wedge-billed woodcreeper, Glyphorynchus spirurus, a Neotropical rainforest bird

Authors

  • B. MILÁ,

    1. Center for Tropical Research, Institute for the Environment, University of California, 619 Charles Young Dr., Los Angeles, CA 90095-1496, USA
    2. Museo Nacional de Ciencias Naturales, CSIC, Madrid 28006, Spain
    3. Department of Ecology and Evolutionary Biology, University of California, 621 Charles Young Dr., Los Angeles, CA 90095, USA
    Search for more papers by this author
  • R. K. WAYNE,

    1. Center for Tropical Research, Institute for the Environment, University of California, 619 Charles Young Dr., Los Angeles, CA 90095-1496, USA
    2. Department of Ecology and Evolutionary Biology, University of California, 621 Charles Young Dr., Los Angeles, CA 90095, USA
    Search for more papers by this author
  • P. FITZE,

    1. Museo Nacional de Ciencias Naturales, CSIC, Madrid 28006, Spain
    Search for more papers by this author
  • T. B. SMITH

    1. Center for Tropical Research, Institute for the Environment, University of California, 619 Charles Young Dr., Los Angeles, CA 90095-1496, USA
    2. Department of Ecology and Evolutionary Biology, University of California, 621 Charles Young Dr., Los Angeles, CA 90095, USA
    Search for more papers by this author

  • B.M. is a postdoctoral researcher currently at the Museo Nacional de Ciencias Naturales in Madrid, Spain, whose research focuses on mechanisms of population divergence and speciation in birds and other vertebrates by means of various approaches, including phylogeography, population genetics and ecomorphology. R.K.W. is a professor at UCLA‘s Department of Ecology and Evolutionary Biology, interested in applying molecular genetic techniques to address questions in population genetics, systematics, genomics and conservation genetics of vertebrates. P.F. is researcher at the Museo Nacional de Ciencias Naturales, where he focuses on behavioural ecology, population genetics and phylogeography of reptiles and birds. T.B.S. is a professor at the Department of Ecology and Evolutionary Biology and the director of the Center for Tropical Research at UCLA. He is interested in evolutionary genetics and ecology, and his research focuses on speciation mechanism, migratory connectivity, bird-parasite interactions and the conservation of tropical vertebrates.

Borja Milá, Fax: +34 915645078; E-mail: bmila@mncn.csic.es

Abstract

Determining the relative roles of vicariance and selection in restricting gene flow between populations is of central importance to the evolutionary process of population divergence and speciation. Here we use molecular and morphological data to contrast the effect of isolation (by mountains and geographical distance) with that of ecological factors (altitudinal gradients) in promoting differentiation in the wedge-billed woodcreeper, Glyphorynchus spirurus, a tropical forest bird, in Ecuador. Tarsus length and beak size increased relative to body size with altitude on both sides of the Andes, and were correlated with the amount of moss on tree trunks, suggesting the role of selection in driving adaptive divergence. In contrast, molecular data revealed a considerable degree of admixture along these altitudinal gradients, suggesting that adaptive divergence in morphological traits has occurred in the presence of gene flow. As suggested by mitochondrial DNA sequence data, the Andes act as a barrier to gene flow between ancient subspecific lineages. Genome-wide amplified fragment length polymorphism markers reflected more recent patterns of gene flow and revealed fine-scale patterns of population differentiation that were not detectable with mitochondrial DNA, including the differentiation of isolated coastal populations west of the Andes. Our results support the predominant role of geographical isolation in driving genetic differentiation in G. spirurus, yet suggest the role of selection in driving parallel morphological divergence along ecological gradients.

Get access to the full text of this article

Ancillary