Insect Development, Thermal Plasticity and Fitness Implications in Changing, Seasonal Environments
Insect Development, Thermal Plasticity and Fitness Implications in Changing, Seasonal Environments
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DOI：
10.1093/icb/icx032
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发表时间：
2017-11-01
影响因子：
2.6
通讯作者：
Kingsolver, Joel G.
中科院分区：
文献类型：
--
作者：
Buckley, Lauren B.;Arakaki, Andrew J.;Kingsolver, Joel G.
历史数据显示，最近的气候变化导致许多动物和植物的季节性时间（物候）提前，特别是在温带和高纬度地区。这些物候变化对昆虫和其他外温动物的种群和适应性的影响是异质的：变暖可以增加发育速率和每年的世代数量（增加适应性），但也可能导致动物与其资源之间的季节性不匹配，并增加对环境变化的暴露（降低适应性）。昆虫种群对温度的发育反应表现出局部适应性，包括较低的发育阈值和完成发育所需的热量，但气候变化可能会破坏幼虫和成虫阶段的季节性时间，并改变种群适应性。我们使用一个全球数据集来研究这些问题，该数据集描述了昆虫发育如何通过两个特征对温度做出反应：发育的较低温度阈值（T-0）和完成发育所需的累积度日数（G）。正如以前的分析所建议的，T-0降低，G增加（绝对）纬度;然而，这些特征和G与纬度之间的关系在分类目的中有显着差异。每年的平均世代数（适应度的度量）随着T-0和G的降低而增加，但这些特征对适应度的影响随纬度变化很大，在更高的（绝对）纬度上对这两个特征的选择更强。然后，我们使用这些特征来预测季节内和跨年（1970-2010）多代的发育时间和温度。季节性驱使发育温度在季节中期达到峰值，世代长度在季节之间下降，特别是在温带地区。我们预测，气候变暖会促进物候学的发展，并增加世代的数量，特别是在高纬度地区。发育温度的增加幅度在不同纬度之间变化不大。季节性世代数量的增加对于经历最大物候进步和变暖的种群来说是最大的。由于气候变化，发育速率和时间的变化将对季节性环境中的选择和适应性产生复杂的影响。
Historical data show that recent climate change has caused advances in seasonal timing (phenology) in many animals and plants, particularly in temperate and higher latitude regions. The population and fitness consequences of these phenological shifts for insects and other ectotherms have been heterogeneous: warming can increase development rates and the number of generations per year (increasing fitness), but can also lead to seasonal mismatches between animals and their resources and increase exposure to environmental variability (decreasing fitness). Insect populations exhibit local adaptation in their developmental responses to temperature, including lower developmental thresholds and the thermal requirements to complete development, but climate change can potentially disrupt seasonal timing of juvenile and adult stages and alter population fitness. We investigate these issues using a global dataset describing how insect developmental responds to temperature via two traits: lower temperature thresholds for development (T-0) and the cumulative degree-days required to complete development (G). As suggested by previous analyses, T-0 decreases and G increases with increasing (absolute) latitude; however, these traits and the relationship between G and latitude varies significantly among taxonomic orders. The mean number of generations per year (a metric of fitness) increases with both decreasing T-0 and G, but the effects of these traits on fitness vary strongly with latitude, with stronger selection on both traits at higher (absolute) latitudes. We then use the traits to predict developmental timing and temperatures for multiple generations within seasons and across years (1970-2010). Seasonality drives developmental temperatures to peak mid-season and for generation lengths to decline across seasons, particularly in temperate regions. We predict that climate warming has advanced phenology and increased the number of generations, particularly at high latitudes. The magnitude of increases in developmental temperature varies little across latitude. Increases in the number of seasonal generations have been greatest for populations experiencing the greatest phenological advancements and warming. Shifts in developmental rate and timing due to climate change will have complex implications for selection and fitness in seasonal environments.