A simple measure of the strength of convergent evolution
Article first published online: 10 MAY 2014
© 2014 The Authors. Methods in Ecology and Evolution published by John Wiley & Sons Ltd on behalf of British Ecological Society.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Methods in Ecology and Evolution
Volume 5, Issue 7, pages 685–693, July 2014
How to Cite
Arbuckle, K., Bennett, C. M., Speed, M. P. (2014), A simple measure of the strength of convergent evolution. Methods in Ecology and Evolution, 5: 685–693. doi: 10.1111/2041-210X.12195
- Issue published online: 15 JUL 2014
- Article first published online: 10 MAY 2014
- Accepted manuscript online: 17 APR 2014 10:34PM EST
- Manuscript Accepted: 1 APR 2014
- Manuscript Received: 24 JAN 2014
- NERC Doctoral Training
- phylogenetic comparative methods;
- phenotypic evolution;
- evolutionary processes;
- functional ecomorphology;
- Convergent evolution, the independent occurrence of phenotypic similarity, is a widespread and common phenomenon. Methods have been developed to identify instances of convergence, but there is a lack of techniques for quantifying the strength of convergence. We therefore investigated whether convergent evolution can be quantified in a meaningful way.
- We have developed a simple metric (the Wheatsheaf index) that provides an index of the strength of convergent evolution incorporating both phenotypic similarity and phylogenetic relatedness. The index is comparable across any quantitative or semiquantitative traits and thus will enable the testing of various hypotheses relating to convergence.
- The index performs well over a range of conditions. We apply it to an empirical example using Anolis lizard ecomorphs to demonstrate how it can be used.
- The Wheatsheaf index provides an additional tool that complements methods aimed at identifying cases of convergent evolution. It will enable cases of convergence to be analysed in more detail, test hypotheses about its mechanics as an evolutionary process and, more generally, the predictability of evolution (how often do we see strong convergence and does this mean evolutionary solutions are limited?).