Data from: Latitudinal and voltinism compensation shape thermal reaction norms for growth rate

Latitudinal variation in thermal reaction norms of key fitness traits may inform about the response of populations to climate warming, yet their adaptive nature and evolutionary potential is poorly known. We assessed the contribution of quantitative genetic, neutral genetic and environmental effects to thermal reaction norms of growth rate for populations of the damselfly Ischnura elegans. Among populations, reaction norms differed primarily in elevation suggesting that time constraints associated with shorter growth seasons in univoltine, high-latitude as well as multivoltine, low-latitude populations selected for faster growth rates. Phenotypic divergence among populations is consistent with selection rather than drift as QST was greater than FST in all cases. QST estimates increased with experimental temperature and were influenced by genotype by environment interactions. Substantial additive genetic variation for growth rate in all populations suggests that evolution of trait means in different environments is not constrained. Heritability of growth rates was higher at high temperature, driven by increased genetic rather than environmental variance. While environment-specific non-additive effects also may contribute to heritability differences among temperatures, maternal effects did not play a significant role (where these could be accounted for). Genotype by environment interactions strongly influenced the adaptive potential of populations, and our results suggest the potential for microevolution of thermal reaction norms in each of the studied populations. In summary, the observed latitudinal pattern in growth rates is adaptive and results from a combination of latitudinal and voltinism compensation. Combined with the evolutionary potential of thermal reaction norms, this may affect populations’ ability to respond to future climate warming.

关键适合度性状的热反应规范（thermal reaction norms）的纬度变异，可为揭示种群应对气候变暖的响应机制提供启示，但其适应性本质与进化潜力却鲜为人知。本研究以蓝尾豆娘（Ischnura elegans）的多个种群为对象，评估了数量遗传、中性遗传与环境效应对其生长速率热反应规范的贡献。种群间的反应规范差异主要体现在平均表型水平上，这表明：一化性高纬度种群与多化性低纬度种群的生长季更短，由此产生的时间约束对更快的生长速率产生了定向选择。种群间的表型分化符合定向选择而非遗传漂变的预期，因为所有案例中的QST均大于FST。QST估计值随实验温度升高而增大，且受基因型-环境互作的显著影响。所有种群的生长速率均存在大量的加性遗传变异，这表明不同环境下的性状均值进化并未受到约束。高温下生长速率的遗传力更高，这一现象由遗传方差（而非环境方差）增大所驱动。尽管环境特异性的非加性效应也可能导致不同温度下的遗传力差异，但母性效应并未发挥显著作用（在可核算母性效应的研究场景中）。基因型-环境互作对种群的适应性潜力具有强烈影响，本研究结果表明，所有被研究种群的热反应规范均存在微进化潜力。综上，观测到的生长速率纬度格局具有适应性，是纬度补偿与化性补偿共同作用的结果。结合热反应规范的进化潜力，这一结果或可影响种群应对未来气候变暖的能力。