Data from: Quantitative genetic divergence and standing genetic (co)variance in thermal reaction norms along latitude

Although the potential to adapt to warmer climate is constrained by genetic trade-offs, our understanding of how selection and mutation shape genetic (co)variances in thermal reaction norms is poor. Using 71 isofemale lines of the fly Sepsis punctum, originating from northern, central and southern European climates, we tested for divergence in juvenile development rate across latitude at five experimental temperatures. To investigate effects of evolutionary history in different climates on standing genetic variation in reaction norms, we further compared genetic (co)variances between regions. Flies were reared on either high or low food resources to explore the role of energy-acquisition in determining genetic trade-offs between different temperatures. Although the latter had only weak effects on the strength and sign of genetic correlations, genetic architecture differed significantly between climatic regions, implying that evolution of reaction norms proceeds via different trajectories at high versus low latitude in this system. Accordingly, regional genetic architecture was correlated to region-specific differentiation. Moreover, hot development temperatures were associated with low genetic variance and stronger genetic correlations compared to cooler temperatures. We discuss the evolutionary potential of thermal reaction norms in light of their underlying genetic architectures, evolutionary histories and the materialization of trade-offs in natural environments.

尽管物种适应气候变暖的潜力受到遗传权衡（genetic trade-offs）的限制，但目前学界对于选择与突变如何塑造热反应规范（thermal reaction norms）中的遗传（共）方差（genetic (co)variances）的认知仍较为匮乏。本研究以源自欧洲北部、中部与南部不同气候区域的71个等雌系（isofemale lines）斑点黑脚蝇（Sepsis punctum）为实验材料，在5个实验温度下检测了其幼体发育速率随纬度的分化情况。为探究不同气候下的演化历史对反应规范中现存遗传变异（standing genetic variation）的影响，我们进一步比较了不同区域间的遗传（共）方差。研究人员将果蝇分别置于高、低两种食物资源条件下饲养，以探索能量获取在调控不同温度间遗传权衡中的作用。尽管食物资源对遗传相关（genetic correlations）的强度与方向仅存在微弱影响，但不同气候区域间的遗传架构（genetic architecture）却存在显著差异，这意味着在本研究体系中，热反应规范的演化在高纬度与低纬度区域遵循不同的轨迹。相应地，区域特异性的遗传架构与区域特有的分化模式存在相关性。此外，相较于低温培养条件，高温发育环境下的遗传方差更低，且遗传相关性更强。最后，我们结合热反应规范的潜在遗传架构、演化历史以及自然环境中遗传权衡的具体表现，探讨了其演化潜力。