Geographic mode of speciation in a mountain specialist Avian family endemic to the Palearctic
Article first published online: 18 APR 2013
© 2013 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.
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Ecology and Evolution
Volume 3, Issue 6, pages 1518–1528, June 2013
How to Cite
Ecology and Evolution 2013; 3(6): 1518–1528
- Issue published online: 12 JUN 2013
- Article first published online: 18 APR 2013
- Manuscript Accepted: 4 MAR 2013
- Manuscript Revised: 27 FEB 2013
- Manuscript Received: 1 FEB 2013
- Fundação para a Ciência e a Tecnologia
- National Geographic Society
- U.S. National Science Foundation
- Allopatric speciation;
- historical biogeography;
Mountains host greater avian diversity than lowlands at the same latitude due to their greater diversity of habitats stratified along an elevation gradient. Here we test whether this greater ecological heterogeneity promotes sympatric speciation. We selected accentors (Prunellidae), an avian family associated with mountains of the Palearctic, as a model system. Accentors differ in their habitat/elevation preferences and south-central Siberia and Himalayan regions each host 6 of the 13 species in the family. We used sequences of the mtDNA ND2 gene and the intron 9 of the Z chromosome specific ACO1 gene to reconstruct a complete species-level phylogeny of Prunellidae. The tree based on joint analysis of both loci was used to reconstruct the family's biogeographic history and to date the diversification events. We also analyzed the relationship between the node age and sympatry, to determine the geographic mode of speciation in Prunellidae. Our data suggest a Miocene origin of Prunellidae in the Himalayan region. The major division between alpine species (subgenus Laiscopus) and species associated with shrubs (subgenus Prunella) and initial diversification events within the latter happened within the Himalayan region in the Miocene and Pliocene. Accentors colonized other parts of the Palearctic during the Pliocene-Pleistocene transition. This spread across the Palearctic resulted in rapid diversification of accentors. With only a single exception dating to 0.91 Ma, lineages younger than 1.5 Ma are allopatric. In contrast, sympatry values for older nodes are >0. There was no relationship between node age and range symmetry. Allopatric speciation (not to include peripatric) is the predominant geographic mode of speciation in Prunellidae despite the favorable conditions for ecological diversification in the mountains and range overlaps among species.