title: Evidence for ecology's role in speciation.
abstract: A principal challenge in testing the role of natural selection in speciation is to connect the build-up of reproductive isolation between populations to divergence of ecologically important traits. Demonstrations of 'parallel speciation', or assortative mating by selective environment, link ecology and isolation, but the phenotypic traits mediating isolation have not been confirmed. Here we show that the parallel build-up of mating incompatibilities between stickleback populations can be largely accounted for by assortative mating based on one trait, body size, which evolves predictably according to environment. In addition to documenting the influence of body size on reproductive isolation for stickleback populations spread across the Northern Hemisphere, we have confirmed its importance through a new experimental manipulation. Together, these results suggest that speciation may arise largely as a by-product of ecological differences and divergent selection on a small number of phenotypic traits.
authors.affiliation: Biological Sciences, University of Wisconsin-Whitewater, Whitewater, Wisconsin 53190, USA. mckinnoj@uww.edu
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: McKinnon
authors.forename: Seiichi
authors.initials: S
authors.lastname: Mori
authors.forename: Benjamin K
authors.initials: BK
authors.lastname: Blackman
authors.forename: Lior
authors.initials: L
authors.lastname: David
authors.forename: David M
authors.initials: DM
authors.lastname: Kingsley
authors.forename: Leia
authors.initials: L
authors.lastname: Jamieson
authors.forename: Jennifer
authors.initials: J
authors.lastname: Chou
authors.forename: Dolph
authors.initials: D
authors.lastname: Schluter
mesh_terms: D000413:Alaska; D000818:Animals; D001824:Body Constitution; D001955:British Columbia; D004463:Ecology; D004777:Environment; D005260:Female; D005399:Fishes / Q000145:classification* / Q000235:genetics / Q000502:physiology*; D005843:Geography; D007055:Iceland; D007564:Japan; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D009664:Norway; D010641:Phenotype; D012098:Reproduction / Q000235:genetics / Q000502:physiology*; D012606:Scotland; D012641:Selection, Genetic; D012726:Sexual Behavior, Animal / Q000502:physiology; D013045:Species Specificity