title: Parasites contribute to ecologically dependent postmating isolation in the adaptive radiation of three-spined stickleback.
abstract: Spatial variation in parasitic infections is common, and has the potential to drive population divergence and the reproductive isolation of hosts. However, despite support from theory and model laboratory systems, little strong evidence has been forthcoming from the wild. Here, we show that parasites are likely to cause reproductive isolation in the adaptive radiation of three-spined stickleback. Adjacent wild populations on the Scottish island of North Uist differ greatly and consistently in the occurrence of different parasites that have substantial effects on fitness. Laboratory-reared fish are more resistant to experimental infection by parasite species from their own population. Furthermore, hybrid backcrosses between the host populations are more resistant to parasites from the parental population to which they are more closely related. These patterns provide strong evidence that parasites can cause ecological speciation, by contributing to selection against migrants and ecologically dependent postmating isolation.
authors: School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
authors: Aliya
authors: A
authors: El Nagar
authors: School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK andrew.maccoll@nottingham.ac.uk.
authors: Andrew D C
authors: 0000-0003-2102-6130
authors: AD
authors: MacColl
mesh_terms: D000818:Animals; D004463:Ecology; D049810:Genetic Speciation; D005828:Genetics, Population; D010271:Parasites; D012098:Reproduction; D060047:Reproductive Isolation; D012606:Scotland; D023701:Smegmamorpha / Q000235:genetics* / Q000469:parasitology*
keywords: Gasterosteus aculeatus; divergent evolution; local adaptation; parasites; speciation