Multigenerational exposure to elevated temperatures leads to a reduction in standard metabolic rate in the wild.
Multigenerational exposure to elevated temperatures leads to a reduction in standard metabolic rate in the wild.
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多代人暴露在高温下会导致野外标准代谢率降低。
DOI：
10.1111/1365-2435.13538
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发表时间：
2020
影响因子：
5.2
通讯作者：
Pilakouta N
中科院分区：
文献类型：
--
作者：
Pilakouta N
鉴于全球气候变化，迫切需要了解和预测人口应对气温上升的能力。代谢率是可能影响应对气候变化能力的关键特征。然而，到目前为止，关于代谢率对温度变化的响应的经验和理论工作产生了喜忧参半的结果和相互矛盾的预测。我们的研究使用一种新的方法来解决这个问题，即比较冰岛地热变暖的湖泊和邻近的常温湖泊中的鱼类数量。这一独特的“自然实验”提供了在小地理范围内经历多代人不同热环境的重复和独立的例子，从而避免了与纬度或海拔比较相关的混淆因素。使用来自三个温暖和三个寒冷栖息地的冰岛刺鱼，我们测量了不同驯化温度范围内的个体代谢率，以获得每个种群的反应标准。我们发现了在相同温度下测量时，来自温暖栖息地的刺鱼的标准代谢率(SMR)较低的一般模式，正如Krogh规则所预测的那样。温暖和寒冷栖息地的刺鱼之间的代谢率差异在更极端的驯化温度下更加明显，这表明在新的条件下释放出隐蔽的遗传变异，这可能揭示出隐藏的进化潜力。我们还发现，异地温热生境之间的代谢率差异大于同源温热生境之间的代谢率差异，这表明当可能在温暖和寒冷生境之间扩散时，基因流动可能会限制生理适应。综上所述，我们的研究表明，在变暖的世界中，鱼类可能会向较低的SMR分化，但这可能取决于不同温热生境之间的连通性和基因流动。
In light of global climate change, there is a pressing need to understand and predict the capacity of populations to respond to rising temperatures. Metabolic rate is a key trait that is likely to influence the ability to cope with climate change. Yet, empirical and theoretical work on metabolic rate responses to temperature changes has so far produced mixed results and conflicting predictions.Our study addresses this issue using a novel approach of comparing fish populations in geothermally warmed lakes and adjacent ambient‐temperature lakes in Iceland. This unique ‘natural experiment’ provides repeated and independent examples of populations experiencing contrasting thermal environments for many generations over a small geographic scale, thereby avoiding the confounding factors associated with latitudinal or elevational comparisons. Using Icelandic sticklebacks from three warm and three cold habitats, we measured individual metabolic rates across a range of acclimation temperatures to obtain reaction norms for each population.We found a general pattern for a lower standard metabolic rate (SMR) in sticklebacks from warm habitats when measured at a common temperature, as predicted by Krogh's rule. Metabolic rate differences between warm‐ and cold‐habitat sticklebacks were more pronounced at more extreme acclimation temperatures, suggesting the release of cryptic genetic variation upon exposure to novel conditions, which can reveal hidden evolutionary potential. We also found a stronger divergence in metabolic rate between thermal habitats in allopatry than sympatry, indicating that gene flow may constrain physiological adaptation when dispersal between warm and cold habitats is possible.In sum, our study suggests that fish may diverge toward a lower SMR in a warming world, but this might depend on connectivity and gene flow between different thermal habitats.A free Plain Language Summary can be found within the Supporting Information of this article.