title: Genetic variation of loci potentially under selection confounds species-genetic diversity correlations in a fragmented habitat.
abstract: Positive species-genetic diversity correlations (SGDCs) are often thought to result from the parallel influence of neutral processes on genetic and species diversity. Yet, confounding effects of non-neutral mechanisms have not been explored. Here, we investigate the impact of non-neutral genetic diversity on SGDCs in high Andean wetlands. We compare correlations between plant species diversity and genetic diversity (GD) calculated with and without loci potentially under selection (outlier loci). The study system includes 2188 specimens from five species (three common aquatic macroinvertebrate and two dominant plant species) that were genotyped for 396 amplified fragment length polymorphism loci. We also appraise the importance of neutral processes on SGDCs by investigating the influence of habitat fragmentation features. Significant positive SGDCs were detected for all five species (mean SGDC = 0.52 ± 0.05). While only a few outlier loci were detected in each species, they resulted in significant decreases in GD and in SGDCs. This supports the hypothesis that neutral processes drive species-genetic diversity relationships in high Andean wetlands. Unexpectedly, the effects on genetic diversity GD of the habitat fragmentation characteristics in this study increased with the presence of outlier loci in two species. Overall, our results reveal pitfalls in using habitat features to infer processes driving SGDCs and show that a few loci potentially under selection are enough to cause a significant downward bias in SGDC. Investigating confounding effects of outlier loci thus represents a useful approach to evidence the contribution of neutral processes on species-genetic diversity relationships.
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad de La Serena, Av. Raúl Bitrán 1305, Casilla 554, La Serena, Chile.
authors.forename: Angeline
authors.initials: A
authors.lastname: Bertin
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad de La Serena, Av. Raúl Bitrán 1305, Casilla 554, La Serena, Chile.|Centro de Estudios Avanzados en Zonas Áridas, Raúl Bitrán 1305, La Serena, Chile.|Instituto de Investigación Multidisciplinar en Ciencia y Tecnología, Universidad de La Serena, Casilla 554, La Serena, Chile.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Gouin
authors.affiliation: Aix Marseille Univ, IMBE, UMR CNRS, IRD, Avignon Univ, Technopole Environm Arbois Mediterrane, BP 80, F-13545 Aix En Provence 04, France.
authors.forename: Alex
authors.initials: A
authors.lastname: Baumel
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad de La Serena, Av. Raúl Bitrán 1305, Casilla 554, La Serena, Chile.|Departamento de Botánica, Universidad de Concepción, Casilla 160-C, Concepción, Chile.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Gianoli
authors.affiliation: Facultad de Ciencias del Mar, Doctorado en Biología y Ecología Aplicada, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile.
authors.forename: Juan
authors.initials: J
authors.lastname: Serratosa
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad de La Serena, Av. Raúl Bitrán 1305, Casilla 554, La Serena, Chile.
authors.forename: Rodomiro
authors.initials: R
authors.lastname: Osorio
authors.affiliation: CNRS, UM, SupAgro, IRD, INRA, UMR 5175 CEFE, EPHE, PSL Research University, F-34293, Montpellier, France.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Manel
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D044822:Biodiversity; D002677:Chile; D014644:Genetic Variation; D005838:Genotype; D010944:Plants / Q000145:classification*; D012641:Selection, Genetic; D053833:Wetlands
keywords: community genetics; connectivity; habitat; high Andean wetlands; outlier loci; species-genetic diversity correlations