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Crest evolution in newts: implications for reconstruction methods, sexual selection, phenotypic plasticity and the origin of novelties
Article first published online: 27 JUN 2011
DOI: 10.1111/j.1420-9101.2011.02340.x
© 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology
Additional Information
How to Cite
WIENS, J. J., SPARREBOOM, M. and ARNTZEN, J. W. (2011), Crest evolution in newts: implications for reconstruction methods, sexual selection, phenotypic plasticity and the origin of novelties. Journal of Evolutionary Biology, 24: 2073–2086. doi: 10.1111/j.1420-9101.2011.02340.x
Publication History
- Issue published online: 12 SEP 2011
- Article first published online: 27 JUN 2011
- Received 21 March 2011; revised 21 May 2011; accepted 24 May 2011
Keywords:
- amphibians;
- ancestral state reconstruction;
- behaviour;
- phenotypic plasticity;
- phylogeny;
- Salamandridae;
- sexual selection
Abstract
The dorsal crest of newts (Salamandridae) is a novel, phenotypically plastic, sexually selected trait that may evolve in association with complex courtship behaviours. We estimated a near-comprehensive, time-calibrated phylogeny for salamandrids and analysed the evolution of their crests and display behaviour. Different models give conflicting reconstructions for crest evolution, showing that likelihood can estimate incorrect ancestral states with strong statistical support. The best-fitting model suggests that crests evolved once and were lost repeatedly, supporting the hypothesis that sexually selected traits may be frequently lost. We demonstrate the correlated evolution of crests and courtship behaviour and show that species with larger numbers of crest-related traits have larger repertoires of behaviours. We also show that phenotypically plastic morphological traits can be maintained over long macroevolutionary timescales (∼25–48 Myr). Finally, we use salamandrids to address how novel structures may arise, and support a model involving the expansion and subdivision of pre-existing structures.