Temperature fluctuations during development reduce male fitness and may limit adaptive potential in tropical rainforest Drosophila.
Temperature fluctuations during development reduce male fitness and may limit adaptive potential in tropical rainforest Drosophila.
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发育过程中的温度波动会降低雄性的适应性，并可能限制热带雨林果蝇的适应潜力。
DOI：
10.1111/jeb.13231
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发表时间：
2018
影响因子：
2.1
通讯作者：
Saxon AD
中科院分区：
文献类型：
--
作者：
Saxon AD
了解生物体通过生理或进化反应耐受热应力的潜力对于快速气候变化至关重要。虽然气候模型预测温度均值和方差都会增加，但这种公差通常是在恒定条件下评估的。我们测试的影响，在发展过程中的温度变化对男性健身的热带雨林果蝇birchii，通过模拟典型的热变化的温暖和凉爽的边缘，其海拔分布，估计遗传力和遗传相关性的健身性状。在温暖（平均24 °C）波动（±3 °C）与恒定条件下饲养的雄性繁殖成功率降低，但在凉爽波动条件（平均17 °C）下则不会，尽管波动在两种温度下都会降低体型。雄性在温暖波动条件下的繁殖成功率与恒定27 °C下的繁殖成功率相似，表明短暂超过临界温度限制与持续压力条件下的适应性成本相似。所有性状都存在大量的可遗传变异。然而，生殖成功性状没有表现出遗传相关性的治疗反映温度变化在海拔极端，这可能会限制在这些生态边缘的进化反应。我们的数据表明，即使是温度变化的小幅度增加，也会威胁到生活在接近其上限温度的热带外温动物，这既通过对适应性的直接影响，也通过限制它们的适应潜力。
Understanding the potential for organisms to tolerate thermal stress through physiological or evolutionary responses is crucial given rapid climate change. Although climate models predict increases in both temperature mean and variance, such tolerances are typically assessed under constant conditions. We tested the effects of temperature variability during development on male fitness in the rainforest flyDrosophila birchii, by simulating thermal variation typical of the warm and cool margins of its elevational distribution, and estimated heritabilities and genetic correlations of fitness traits. Reproductive success was reduced for males reared in warm (mean 24 °C) fluctuating (±3 °C) vs. constant conditions but not in cool fluctuating conditions (mean 17 °C), although fluctuations reduced body size at both temperatures. Male reproductive success under warm fluctuating conditions was similar to that at constant 27 °C, indicating that briefly exceeding critical thermal limits has similar fitness costs to continuously stressful conditions. There was substantial heritable variation in all traits. However, reproductive success traits showed no genetic correlation between treatments reflecting temperature variation at elevational extremes, which may constrain evolutionary responses at these ecological margins. Our data suggest that even small increases in temperature variability will threaten tropical ectotherms living close to their upper thermal limits, both through direct effects on fitness and by limiting their adaptive potential.