These authors contributed equally to this paper.
Replicated radiations of the alpine genus Androsace (Primulaceae) driven by range expansion and convergent key innovations
Article first published online: 11 JUN 2013
© 2013 John Wiley & Sons Ltd
Journal of Biogeography
Volume 40, Issue 10, pages 1874–1886, October 2013
How to Cite
Roquet, C., Boucher, F. C., Thuiller, W., Lavergne, S. (2013), Replicated radiations of the alpine genus Androsace (Primulaceae) driven by range expansion and convergent key innovations. Journal of Biogeography, 40: 1874–1886. doi: 10.1111/jbi.12135
- Issue published online: 17 SEP 2013
- Article first published online: 11 JUN 2013
- European Research Council. Grant Number: 281422
- French ANR EVORANGE. Grant Number: ANR-09-PEXT-011
- École Polytechnique
- cushion plants;
- evolutionary determinism;
- historical contingency;
- long-distance dispersal;
- speciation rates
We still have limited understanding of the contingent and deterministic factors that have fostered the evolutionary success of some species lineages over others. We investigated how the interplay of intercontinental migration and key innovations promoted diversification of the genus Androsace.
Mountain ranges and cold steppes of the Northern Hemisphere.
We reconstructed ancestral biogeographical ranges at regional and continental scales by means of a dispersal–extinction–cladogenesis analysis using dated Bayesian phylogenies and contrasting two migration scenarios. Based on diversification analyses under two frameworks, we tested the influence of life form on speciation rates and whether diversification has been diversity-dependent.
We found that three radiations occurred in this genus, at different periods and on different continents, and that life form played a critical role in the history of Androsace. Short-lived ancestors first facilitated the expansion of the genus' range from Asia to Europe, while cushions, which appeared independently in Asia and Europe, enhanced species diversification in alpine regions. One long-distance dispersal event from Europe to North America led to the diversification of the nested genus Douglasia. We found support for a model in which speciation of the North American–European clade is diversity-dependent and close to its carrying capacity, and that the diversification dynamics of the North American subclade are uncoupled from this and follow a pure birth process.
The contingency of past biogeographical connections combined with the evolutionary determinism of convergent key innovations may have led to replicated radiations of Androsace in three mountain regions of the world. The repeated emergence of the cushion life form was a convergent key innovation that fostered radiation into alpine habitats. Given the large ecological similarity of Androsace species, allopatry may have been the main mode of speciation.