title: Locally adapted traits maintained in the face of high gene flow.
abstract: Gene flow between phenotypically divergent populations can disrupt local adaptation or, alternatively, may stimulate adaptive evolution by increasing genetic variation. We capitalised on historical Trinidadian guppy transplant experiments to test the phenotypic effects of increased gene flow caused by replicated introductions of adaptively divergent guppies, which were translocated from high- to low-predation environments. We sampled two native populations prior to the onset of gene flow, six historic introduction sites, introduction sources and multiple downstream points in each basin. Extensive gene flow from introductions occurred in all streams, yet adaptive phenotypic divergence across a gradient in predation level was maintained. Descendants of guppies from a high-predation source site showed high phenotypic similarity with native low-predation guppies in as few as ~12 generations after gene flow, likely through a combination of adaptive evolution and phenotypic plasticity. Our results demonstrate that locally adapted phenotypes can be maintained despite extensive gene flow from divergent populations.
authors.affiliation: Department of Biology, Colorado State University, 1878 Campus Delivery, Fort Collins, CO, 80523, USA.
authors.forename: S W
authors.initials: SW
authors.lastname: Fitzpatrick
authors.forename: J C
authors.initials: JC
authors.lastname: Gerberich
authors.forename: J A
authors.initials: JA
authors.lastname: Kronenberger
authors.forename: L M
authors.initials: LM
authors.lastname: Angeloni
authors.forename: W C
authors.initials: WC
authors.lastname: Funk
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000818:Animals; D005260:Female; D051456:Gene Flow; D056084:Genetic Fitness; D005828:Genetics, Population; D005838:Genotype; D008297:Male; D018895:Microsatellite Repeats; D010641:Phenotype; D011036:Poecilia / Q000235:genetics*; D011235:Predatory Behavior
keywords: Adaptive divergence; Poecilia reticulata; eco-evolutionary dynamics; gene flow; natural selection