Ectotherms can respond to global warming via evolutionary change of their upper thermal limits (CTmax ). Thus, the estimation of CTmax and its evolutionary potential is crucial to determine their vulnerability to global warming. However, CTmax estimations depend on the thermal stress intensity, and it is not completely clear whether its evolutionary capacity can be affected. Here, we performed an artificial selection experiment to increase heat tolerance using fast- and slow-ramping selection protocols in Drosophila subobscura. We found that heat tolerance evolved in both selection protocols, exhibiting similar evolutionary change rates and realized heritabilities. Additionally, we estimated the thermal performance curves (TPC) to evaluate correlated responses to selection on heat tolerance. We detected that thermal optimum increased in fast-ramping selection lines, but with a cost at the thermal performance breadth. Conversely, we did not detect changes in the TPC for the slow-ramping selection lines, indicating that thermal stress intensity has important effects on the evolution of thermal physiology of ectotherms. These findings, together with previous studies in D. subobscura reporting interpopulation variability and significant heritabilities for heat tolerance, suggest that evolutionary change can contribute to insect persistence in thermally changing environments and adaptation to global warming conditions.

中文翻译：

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Drosophila subobscura 在对比热选择下的耐热性和热性能曲线的实验演变。

变温动物可以通过其热上限 (CTmax) 的进化变化来应对全球变暖。因此，估计 CTmax 及其进化潜力对于确定它们对全球变暖的脆弱性至关重要。然而，CTmax 估计取决于热应力强度，其进化能力是否会受到影响尚不完全清楚。在这里，我们在 Drosophila subobscura 中使用快速和慢速斜坡选择协议进行了人工选择实验，以提高耐热性。我们发现耐热性在两种选择方案中都在进化，表现出相似的进化变化率和实现的遗传力。此外，我们估计了热性能曲线 (TPC) 以评估对耐热性选择的相关响应。我们检测到在快速斜坡选择线中热优化增加，但在热性能广度上有代价。相反，我们没有检测到缓慢渐变选择线的 TPC 变化，表明热应力强度对变温动物热生理学的演变具有重要影响。这些发现，连同先前在 D. subobscura 中报告的种群间变异性和耐热性的显着遗传性的研究，表明进化变化有助于昆虫在热变化环境中的持久性和对全球变暖条件的适应。表明热应力强度对变温动物的热生理演化具有重要影响。这些发现，连同先前在 D. subobscura 中报告的种群间变异性和耐热性的显着遗传性的研究，表明进化变化有助于昆虫在热变化环境中的持久性和对全球变暖条件的适应。表明热应力强度对变温动物的热生理演化具有重要影响。这些发现，连同先前在 D. subobscura 中报告的种群间变异性和耐热性的显着遗传性的研究，表明进化变化有助于昆虫在热变化环境中的持久性和对全球变暖条件的适应。