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

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 QST -FST comparisons. Despite strong neutral differentiation (mean FST = 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.

农业景观内的静水淡水系统反复遭受农药污染，可能会影响非靶标生物的种群演化，尤其是生命周期完全水生且扩散能力较低的物种。因此，污染物的进化影响问题对于生态毒理学家而言具有重要的理论意义。本研究以淡水腹足类动物静水椎实螺（Lymnaea stagnalis）为对象，采集了14个来自不同农药及其他人为活动压力环境的种群，探究了历史农药暴露对种群遗传分化的影响。研究通过QST-FST比较，检验了种群适应性分化的假说，共涉及11个生活史性状。尽管存在较强的中性分化（平均FST = 0.291），但5个成体性状或参数受到歧化选择作用。与之相对，2个早期表达性状的模式与统一选择或性状渠化的预期相符，另有4个成体性状表现为中性进化。歧化选择模式大多与生境效应相符，具体表现为池塘种群与沟渠、渠道种群间的分化。相较而言，尽管孵化速率受损与全球性人为压力存在关联，但农药及其他人类活动压力与进化模式的相关性较弱。总体而言，本研究在这种被用作生态毒理学模型的物种中，发现中性标记与适合度相关性状均存在较高的遗传变异，为生态风险评估中需纳入种群响应的遗传与进化组分这一需求提供了实证支持。