Data from: Predictability rather than amplitude of temperature fluctuations determines stress resistance in a natural population of Drosophila simulans

The adaptability of organisms to novel environmental conditions depends on the amount of genetic variance present in the population as well as on the ability of individuals to adjust their phenotype through phenotypic plasticity. Here, we investigated the phenotypic plasticity induced by a single generation's exposure to three different temperature regimes with respect to several life-history and stress-resistance traits in a natural population of Drosophila simulans. We studied a constant as well as a predictably and an unpredictably fluctuating temperature regime. We found high levels of phenotypic plasticity among all temperature regimes, suggesting a strong influence of both temperature fluctuations and their predictability. Increased heat tolerance was observed for flies developed in both types of fluctuating thermal environments compared with flies developed in a constant environment. We suggest that this was due to beneficial hardening when developing in either fluctuating temperature environment. To our surprise, flies that developed in constant and predictably changing environments were similar to each other in most traits when compared to flies from the unpredictably fluctuating environment. The unpredictably changing thermal environment imposed the most stressful condition, resulting in the lowest performance for stress-related traits, even though the absolute temperature changes never exceeded that of the predictably fluctuating environment. The overall decreased stress resistance of flies in the unpredictably fluctuating environment may be the consequence of maladaptive phenotypic plasticity in this setting, indicating that the adaptive value of plasticity depends on the predictability of the environment.生物体对新型环境条件的适应能力，既取决于种群中存在的遗传变异量，也依赖于个体通过表型可塑性（phenotypic plasticity）调整自身表型的能力。本研究以拟果蝇（Drosophila simulans）的自然种群为研究对象，探究了单代暴露于三种不同温度制度下所诱导的表型可塑性，涉及多项生活史性状与抗逆性状。我们设置了恒定温度、可预测波动温度以及不可预测波动温度三种温度制度。研究发现，所有温度制度组均表现出较高水平的表型可塑性，表明温度波动及其可预测性均对表型可塑性具有显著影响。相较于恒定环境中发育的果蝇，两种波动热环境下发育的果蝇均表现出更高的耐热性，我们推测这是因为在波动温度环境中发育时，果蝇获得了有益的热硬化效应。令人意外的是，与不可预测波动环境组的果蝇相比，恒定环境与可预测波动环境组的果蝇在多数性状上表现相似。尽管不可预测波动热环境的绝对温度变化幅度并未超过可预测波动环境，但其施加的胁迫压力最大，导致与抗逆相关的性状表现最差。不可预测波动环境中果蝇的整体抗逆性下降，可能是该环境下表型可塑性出现适应不良的结果，这表明可塑性的适应价值取决于环境的可预测性。