title: Hybridisation and diversification in the adaptive radiation of clownfishes.
abstract: BACKGROUND
  The importance of hybridisation during species diversification has long been debated among evolutionary biologists. It is increasingly recognised that hybridisation events occurred during the evolutionary history of numerous species, especially during the early stages of adaptive radiation. We study the effect of hybridisation on diversification in the clownfishes, a clade of coral reef fish that diversified through an adaptive radiation process. While two species of clownfish are likely to have been described from hybrid specimens, the occurrence and effect of hybridisation on the clade diversification is yet unknown.
  
  
  RESULTS
  We generate sequences of three mitochondrial genes to complete an existing dataset of nuclear sequences and document cytonuclear discordance at a node, which shows a drastic increase of diversification rate. Then, using a tree-based jack-knife method, we identify clownfish species likely stemming from hybridisation events. Finally, we use molecular cloning and identify the putative parental species of four clownfish specimens that display the morphological characteristics of hybrids.
  
  
  CONCLUSIONS
  Our results show that consistently with the syngameon hypothesis, hybridisation events are linked with a burst of diversification in the clownfishes. Moreover, several recently diverged clownfish lineages likely originated through hybridisation, which indicates that diversification, catalysed by hybridisation events, may still be happening.
authors.affiliation: Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland. glenn.litsios@unil.ch.|Swiss Institute of Bioinformatics, Génopode, Quartier Sorge, 1015, Lausanne, Switzerland. glenn.litsios@unil.ch.
authors.forename: Glenn
authors.initials: G
authors.lastname: Litsios
authors.affiliation: Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland. nicolas.salamin@unil.ch.|Swiss Institute of Bioinformatics, Génopode, Quartier Sorge, 1015, Lausanne, Switzerland. nicolas.salamin@unil.ch.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Salamin
mesh_terms: D000818:Animals; D005075:Biological Evolution; D049810:Genetic Speciation; D006824:Hybridization, Genetic; D010473:Perciformes / Q000145:classification* / Q000235:genetics*; D010802:Phylogeny