Laboratory of Evolutionary Stress Ecology and Ecotoxicology, University of Leuven, Leuven, Belgium.
Department of Wetland Ecology, Doñana Biological Station (EBD-CSIC), Seville, Spain.
J Anim Ecol. 2021 Jul;90(7):1666-1677. doi: 10.1111/1365-2656.13482. Epub 2021 Apr 7.
Many species that are moving polewards encounter novel thermal regimes to which they have to adapt. Therefore, rapid evolution of thermal tolerance and of thermal plasticity in fitness-related traits in edge populations can be crucial for the success and speed of range expansions. We tested for adaptation in cold tolerance and in life history, behavioural and physiological traits and their thermal plasticity during a poleward range expansion. We reconstructed the thermal performance curves of life history (survival, growth and development rates), behaviour (food intake) and cold tolerance (chill coma recovery time) in the aquatic larval stage of the damselfly Ischnura elegans that is currently showing a poleward range expansion in northern Europe. We studied larvae from three edge and three core populations using a common-garden experiment. Consistent with the colder annual temperatures, larvae at the expansion front evolved an improved cold tolerance. The edge populations showed no overall (across temperatures) evolution of a faster life history that would improve their range-shifting ability. Moreover, consistent with damselfly edge populations from colder latitudes, edge populations evolved at the highest rearing temperature (28°C) a faster development rate, likely to better exploit the rare periods with higher temperatures. This was associated with a higher food intake and a lower metabolic rate. In conclusion, our results suggest that the edge populations rapidly evolved adaptive changes in trait means and thermal plasticity to the novel thermal conditions at the edge front. Our results highlight the importance of considering besides trait plasticity and the evolution of trait means, also the evolution of trait plasticity to improve forecasts of responses to climate change.
许多向极地迁移的物种会遇到新的热环境，它们必须适应这些环境。因此，边缘种群中与适应性相关的热耐受性和热塑性的快速进化对于成功和快速扩展范围可能至关重要。我们在北极范围扩展过程中测试了耐寒性和生活史、行为和生理特征及其热塑性的适应性。我们重建了目前在北欧出现北极范围扩展的蜻蜓属 Ischnura elegans 的水生幼虫阶段的生活史（存活率、生长和发育速度）、行为（食物摄入量）和耐寒性（冷昏迷恢复时间）的热性能曲线。我们使用共同养殖实验研究了来自三个边缘种群和三个核心种群的幼虫。与年度温度较低一致，处于扩展前沿的幼虫进化出了更好的耐寒性。边缘种群在整个温度范围内并没有表现出更快的生活史进化，这将提高它们的范围转移能力。此外，与来自较冷纬度的蜻蜓边缘种群一致，边缘种群在最高养殖温度（28°C）下进化出更快的发育速度，可能更好地利用罕见的高温期。这与更高的食物摄入量和更低的代谢率有关。总之，我们的研究结果表明，边缘种群迅速进化出适应新的前沿热条件的特征平均值和热塑性变化。我们的研究结果强调了除了考虑特征可塑性和特征平均值的进化之外，还需要考虑特征可塑性的进化，以提高对气候变化响应的预测。
