Phenotypic plasticity and adaptive evolution contribute to advancing flowering phenology in response to climate change

Anthropogenic climate change has already altered the timing of major life history transitions, such as the initiation of reproduction. Both phenotypic plasticity and adaptive evolution can underlie rapid phenological shifts in response to climate change but their relative contributions are poorly understood. Here, we combine a continuous 38-year field survey with quantitative genetic field experiments to assess adaptation in the context of climate change. We focused on Boechera stricta (Brassicaeae), a mustard native to the U.S. Rocky Mountains. Flowering phenology advanced significantly from 1973-2011, and was strongly associated with warmer temperatures and earlier snowmelt dates. Strong directional selection favored earlier flowering in contemporary environments (2010-2011). Climate change could drive this directional selection, and promote even earlier flowering as temperatures continue to increase. Our quantitative genetic analyses predict a response to selection of 0.2 to 0...人为气候变化已改变诸多重要生活史转变的发生时序，例如繁殖启动时刻。表型可塑性（phenotypic plasticity）与适应性进化（adaptive evolution）均可作为响应气候变化的快速物候转变（phenological shifts）的基础，但二者的相对贡献迄今仍未明晰。本研究结合长达38年的连续野外调查与数量遗传野外实验（quantitative genetic field experiments），旨在评估气候变化背景下的适应性演化过程。研究以原产于美国落基山脉的十字花科（Brassicaceae）植物细茎南芥（Boechera stricta）为对象。1973年至2011年间，该物种的开花物候（flowering phenology）显著提前，且与气温升高、融雪日期提前呈显著相关。2010至2011年的当代环境中，强定向选择（directional selection）偏好更早开花的个体。气候变化可驱动这类定向选择，并随气温持续升高进一步推动开花时间提前。本研究的数量遗传分析预测，选择响应（response to selection）范围为0.2至0……