Evolution and plasticity of "arrive and survive" phenotypes driving parallel range shifts in the wild.

许多物种正在经历向高纬度和高海拔地区迁移的过程，这是对气候变化最显著和最重要的生物反应之一。从历史上看，研究人员认为范围的变化仅仅是为了追踪合适的气候而分散的生态过程。然而，我们现在知道，范围的变化实际上也涉及快速的进化变化，反映了：生态位的变化和生态位的扩展，扩散的增加，以及中性遗传变异模式的改变。然而，我们对每一种进化变化的机制和显著性知之甚少，这限制了我们预测范围变化和估计它们对高纬度或高海拔群落的潜在影响的能力。最近的研究表明，DNA内源性表观遗传修饰的变化可能在范围变化和相关适应中发挥核心作用。这是因为这种表观遗传修饰代表了一种提高性状表达灵活性的方法，使个体能够在不断扩大的范围边缘更好地应对新环境。事实上，表观遗传变异往往比遗传变异更能预测物种的生态位极限。然而，遗传变异和表观遗传变异在极地范围扩展中的作用从未被正式比较过，无论是解释能力还是预测能力。在这个建议中，我们的目标是进行一个景观尺度的研究，以发现遗传变异和表观遗传模式，可靠地预测和反映范围移动的适应和速率。在这项工作中，我们建议使用蓝尾豆娘（Ischnura elegans）这一已建立的范围转移进化动力学模型研究系统。这一标志性物种受到温度的强烈限制，目前正在迅速向高纬度地区扩张，以应对气候变化，这与先前描述的生态位宽度、竞争能力和分散表型的进化变化有关。秀丽隐杆线虫在地理上分布广泛，具有发达的基因组资源、高质量的公民科学数据和对入侵栖息地的生态影响，为研究野外平行范围转移进化过程提供了理想的系统。为了评估遗传和表观遗传过程对范围移动的相对重要性，我们将在秀丽隐杆线虫的范围北缘建立四个独立的平行范围移动样带。我们将把实地抽样与实验室实验结合起来，建立变异的驱动因素和生态进化模型，以揭示关键过程和预测。这项提议的工作将提供第一个可靠的测试，来证明遗传和表观遗传过程是如何通过它们对扩散和热适应（我们称之为“到达并生存”的表型）的影响，促进范围向高纬度地区转移的。我们验证的预测模型将进一步确定不同遗传和表观遗传过程的相对重要性，并为预测人类世的范围移动和适应速率提供一个平台。

Many species are undergoing contemporary range shifts to higher latitudes and elevations, representing one of the most dramatic and consequential biotic responses to climate change. Historically, researchers assumed that range shifts simply involved ecological processes of dispersal to track suitable climates. However, we now know that range shifts in fact also involve rapid evolutionary change, reflecting: niche shifts and niche expansion, increases in dispersal, and altered patterns of neutral genetic variation. However, the mechanisms and salience of each of these evolutionary shifts are poorly understood, limiting our ability to predict range shifts and estimate their potential impact on high latitude or high elevation communities.Recent work suggests that shifts in endogenous, epigenetic modifications to DNA may play a central role in enabling range shifts and associated adaptations. This is because such epigenetic modifications represent a way to achieve improved flexibility in trait expression, enabling individuals to better respond to novel environments at the expanding range edge. In fact, epigenetic variation is often a better predictor than genetic variation in predicting species' niche limits. However, the role genetic vs. epigenetic variation in enabling poleward range expansions has never been formally compared, for either explanatory power or predictive ability.In this proposal we aim to conduct a landscape scale study to discover the genetic variants and epigenetic patterns that reliably predict and reflect range shifting adaptations and rates. For this work we propose to use an established model study system for range shifting evolutionary dynamics, the blue-tailed damselfly Ischnura elegans. This iconic species is strongly limited by temperature, and is currently undergoing rapid range expansion into higher latitudes in response to climate change, associated with previously-described evolutionary shifts in niche breadth, competitive ability, and dispersal phenotypes. Being geographically widespread, with well-developed genomic resources, high-quality citizen science data, and documented ecological impacts on invaded habitats, I. elegans provides the ideal system to study range shift evolutionary processes in parallel in the wild.To evaluate the relative importance of genetic and epigenetic processes for range shifting, we will establish four, independent, parallel range shift transects at the northern margin of I. elegans' range. We will combine field sampling with laboratory experiments, to establish drivers of variation, and eco-evolutionary modelling, to uncover key processes and predictions. The proposed work will provide a first, robust test of how genetic and epigenetic processes facilitate range shifts into higher latitudes, via their effects on dispersal and thermal adaptations (what we coin 'arrive and survive' phenotypes). Our validated forecasting models will further establish the relative importance of different genetic and epigenetic processes, and provide a platform for predicting rates of range shifting and adaptation in the Anthropocene.