PHYLOGENETIC INFERENCE OF NUPTIAL TRAIT EVOLUTION IN THE CONTEXT OF ASYMMETRICAL INTROGRESSION IN NORTH AMERICAN DARTERS (TELEOSTEI)
Article first published online: 11 OCT 2012
© 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Volume 67, Issue 2, pages 388–402, February 2013
How to Cite
Harrington, R. C., Benavides, E. and Near, T. J. (2013), PHYLOGENETIC INFERENCE OF NUPTIAL TRAIT EVOLUTION IN THE CONTEXT OF ASYMMETRICAL INTROGRESSION IN NORTH AMERICAN DARTERS (TELEOSTEI). Evolution, 67: 388–402. doi: 10.1111/j.1558-5646.2012.01797.x
- Issue published online: 28 JAN 2013
- Article first published online: 11 OCT 2012
- Accepted manuscript online: 8 SEP 2012 11:55AM EST
- Received April 27, 2012 Accepted August 5, 2012
- gene flow;
- morphological evolution;
Introgressive hybridization and incomplete lineage sorting complicate the inference of phylogeny, and available species-tree methods do not simultaneously account for these processes. Both hybridization and ancestral polymorphism have been invoked to explain divergent phylogenies inferred from different datasets for Stigmacerca, a clade of 11 North American darter species. Species of Stigmacerca are characterized by a mating system involving parental care with males guarding nesting territories and fertilized eggs. Males of four species of Stigmacerca develop egg-mimic nuptial structures on their second dorsal fins during the breeding season. Previous phylogenies suggest contrasting scenarios for the evolution of this nuptial trait. Using a combination of coalescent-based methods, we analyzed a dataset comprising a mitochondrial gene and 15 nuclear loci to estimate relationships and simultaneously test for introgressive hybridization. Our analyses identified several instances of interspecific gene flow involving both cytoplamsmic haplotypes and nuclear alleles. The new phylogeny was used to infer a single origin and recent loss of egg-mimic structures in Stigmacerca and led to the discovery of a phylogenetically distinct species. Our results highlight the limited strategies available to account for introgressive hybridization in the inference of species relationships and the likely effects of this process on reconstructing trait evolution.