Evolutionary mechanisms underpinning fitness response to multiple stressors in Daphnia

Multiple stressors linked to anthropogenic activities can influence how organisms adapt and evolve. So far, a consensus on how multiple stressors drive adaptive trajectories in natural populations has not been reached. Some meta-analysis reports show predominance of additive effects of stressors on ecological endpoints (e.g. fecundity, mortality), whereas others show synergistic effects more frequently. Moreover, it is unclear what mechanisms of adaptation underpin responses to complex environments. Here, we use populations of the crustacean Daphnia magna resurrected from different times in the past to investigate mechanisms of adaptation to multiple stressors, and to understand how historical exposure to environmental stress shapes adaptive responses of modern populations. Using common garden experiments on resurrected modern and historical populations, we investigate: i) whether exposure to one stress results in higher tolerance to a second stressor; ii) the mechanisms of adaptatio...与人类活动相关的多重环境胁迫因子，可影响生物的适应与演化过程。迄今为止，学界尚未就多重胁迫因子如何驱动自然种群的适应性演化轨迹达成共识。部分元分析(meta-analysis)研究表明，胁迫因子对生态效应终点（如繁殖力、死亡率）的影响多表现为加性效应；而另有部分研究则更频繁地观测到协同效应。此外，目前仍不清楚支撑生物应对复杂环境响应的适应性机制具体为何。 本研究以可复活自不同历史时期的甲壳类动物大型溞(Daphnia magna)种群为研究材料，探究生物应对多重胁迫因子的适应性机制，并解析历史环境胁迫暴露如何塑造现代种群的适应性响应。本研究通过对复活的历史种群与现代种群开展同质园实验，旨在探究：① 预暴露于一种胁迫因子是否可提升生物对第二种胁迫因子的耐受能力；② 支撑此类响应的适应性机制……