title: Anthropogenic transport of species across native ranges: unpredictable genetic and evolutionary consequences.
abstract: Human activities are responsible for the translocation of vast amounts of organisms, altering natural patterns of dispersal and gene flow. Most research to date has focused on the consequences of anthropogenic transportation of non-indigenous species within introduced ranges, with little research focusing on native species. Here, we compared genetic patterns of the sessile marine invertebrate, Ciona intestinalis, which has highly restricted dispersal capabilities. We collected individuals in a region of the species' native range where human activities that are known to facilitate the artificial spread of species are prevalent. Using microsatellite markers, we revealed highly dissimilar outcomes. First, we found low levels of genetic differentiation among sites separated by both short and large geographical distances, indicating the presence of anthropogenic transport of genotypes, and little influence of natural geographical barriers. Second, we found significant genetic differentiation in pairwise comparisons among certain sites, suggesting that other factors besides artificial transport (e.g. natural dispersal, premodern population structure) may be shaping genetic patterns. Taken together, we found dissimilar patterns of population structure in a highly urbanized region that could not be predicted by artificial transport alone. We conclude that anthropogenic activities alter genetic composition of native ranges, with unknown consequences for species' evolutionary trajectories.
authors.affiliation: Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, European Way, Southampton SO14 3ZH, UK.
authors.forename: Jamie
authors.initials: J
authors.lastname: Hudson
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7144, Department 'Adaptation and Diversity in Marine Environment', Team Div&Co, Station Biologique de Roscoff, 29682 Roscoff, France.
authors.forename: Frédérique
authors.identifier: 0000-0001-5603-9527
authors.initials: F
authors.lastname: Viard
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7144, Department 'Adaptation and Diversity in Marine Environment', Team Div&Co, Station Biologique de Roscoff, 29682 Roscoff, France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Roby
authors.affiliation: Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, European Way, Southampton SO14 3ZH, UK Department of Zoology, University of Johannesburg, Auckland Park 2006, Johannesburg, South Africa m.rius@soton.ac.uk.
authors.forename: Marc
authors.identifier: 0000-0002-2195-6605
authors.initials: M
authors.lastname: Rius
mesh_terms: D063147:Animal Distribution; D000818:Animals; D005075:Biological Evolution; D002938:Ciona intestinalis / Q000235:genetics*; D004739:England; D005602:France; D005838:Genotype; D058865:Introduced Species; D018895:Microsatellite Repeats
keywords: dispersal pathways; larval transport; population connectivity; range shifts; tunicates