Environmental versus anthropogenic effects on population adaptive divergence in the freshwater snail Lymnaea stagnalis

PLoS One. 2014 Sep 10;9(9):e106670. doi: 10.1371/journal.pone.0106670. eCollection 2014.

Abstract

Repeated pesticide contaminations of lentic freshwater systems located within agricultural landscapes may affect population evolution in non-target organisms, especially in species with a fully aquatic life cycle and low dispersal ability. The issue of evolutionary impact of pollutants is therefore conceptually important for ecotoxicologists. The impact of historical exposure to pesticides on genetic divergence was investigated in the freshwater gastropod Lymnaea stagnalis, using a set of 14 populations from contrasted environments in terms of pesticide and other anthropogenic pressures. The hypothesis of population adaptive divergence was tested on 11 life-history traits, using Q(ST)-F(ST) comparisons. Despite strong neutral differentiation (mean F(ST) = 0.291), five adult traits or parameters were found to be under divergent selection. Conversely, two early expressed traits showed a pattern consistent with uniform selection or trait canalization, and four adult traits appeared to evolve neutrally. Divergent selection patterns were mostly consistent with a habitat effect, opposing pond to ditch and channel populations. Comparatively, pesticide and other human pressures had little correspondence with evolutionary patterns, despite hatching rate impairment associated with global anthropogenic pressure. Globally, analyses revealed high genetic variation both at neutral markers and fitness-related traits in a species used as model in ecotoxicology, providing empirical support for the need to account for genetic and evolutionary components of population response in ecological risk assessment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological* / drug effects
  • Agriculture
  • Animals
  • Environment*
  • Evolution, Molecular
  • Genetic Drift
  • Humans
  • Lymnaea / drug effects
  • Lymnaea / genetics
  • Lymnaea / physiology*
  • Pesticides / pharmacology
  • Selection, Genetic / drug effects

Substances

  • Pesticides

Associated data

  • Dryad/10.5061/dryad.G4D30

Grants and funding

AB had a PhD fellowship from the French National Institute for Agricultural Research (INRA: CJS Contrat Jeune Scientifique). Experiment and data acquisition were funded by the French National Institute for Agricultural research (INRA: AIP Bioressources and EFPA Department PI). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.