Present address: School of Biological Sciences, University of Nebraska, Lincoln, NE, USA.
Testing the molecular and evolutionary causes of a ‘leapfrog’ pattern of geographical variation in coloration
Article first published online: 19 NOV 2010
© 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology
Journal of Evolutionary Biology
Volume 24, Issue 2, pages 402–414, February 2011
How to Cite
CADENA, C. D., CHEVIRON, Z. A. and FUNK, W. C. (2011), Testing the molecular and evolutionary causes of a ‘leapfrog’ pattern of geographical variation in coloration. Journal of Evolutionary Biology, 24: 402–414. doi: 10.1111/j.1420-9101.2010.02175.x
- Issue published online: 13 JAN 2011
- Article first published online: 19 NOV 2010
- Received 20 February 2010; revised 13 October 2010; accepted 15 October 2010.
- genetic drift;
- melanocortin-1 receptor;
- natural selection;
- parallel evolution;
- sexual selection;
- social selection;
Understanding the mechanisms accounting for the evolution of phenotypic diversity is central to evolutionary biology. We use molecular and phenotypic data to test hypotheses for ‘leapfrog’ patterns of geographical variation, in which phenotypically similar, disjunct populations are separated by distinct populations of the same species. Phylogenetic reconstructions revealed independent evolution of melanic plumage characters in different populations in the Neotropical avian genus Arremon. Thus, phenotypic similarities between distant populations cannot be explained by close phylogenetic affinity. Nor can they be attributed to recurring mutations in the MC1R gene, a locus involved in melanic pigmentation. A coalescent analysis indicates that plumage traits have become fixed at a faster rate than expected under genetic drift, suggesting that selection underlies their repeated evolution. In contrast to views that genetic drift drives phenotypic differentiation in Neotropical montane birds, our results imply that geographical variation preceding speciation may reflect the action of deterministic selective processes.