Collaborative Research: Tracking fine-scale selection to temperature at the invasion front of a highly dispersive marine predator

海洋入侵物种对海洋生态系统和依赖海洋生态系统的经济体构成严重和持续的风险。了解这些物种如何快速适应新环境是预防和管理入侵的关键。传统上，重点一直放在入侵物种的固有特征和灵活性上，忽略了引入后进化变化的潜力。然而，最近的研究表明，一些海洋物种可能进化出特定的基因组特征，这些特征允许在短短的一代中进行高效选择。该项目测试了基因组特征在允许海洋入侵物种在新海岸生存和繁荣方面的重要性。其重点是影响力大的入侵性欧洲绿色蟹，自1989年以来，这种蟹已蔓延到北美洲西海岸1 500多公里，最近开始扩展到萨利希海。该项目跟踪了绿色蟹入侵新环境的最早阶段，预计该物种将对生态和经济产生重大影响。在整个西海岸，随着时间和空间的推移，遗传差异被跟踪，重点是在萨利希海发现的螃蟹，该物种目前正在扩大。遗传数据与海洋学建模相辅相成，预测绿色蟹向萨利希海和整个西海岸的扩散。最后，有针对性的测序和事先采样用于探测这些变化背后的基因组特征，并确定相同的特征是否在物种在其他海岸的入侵成功中发挥了作用。这个项目的采样是由华盛顿海洋赠款的螃蟹小组进行的，这是一个广泛的推广和监测项目，主要由数百名志愿者提供动力，他们监测萨利希海3,000英里海岸线上的绿色螃蟹。该项目的成果将与这些志愿者和其他利益相关者分享，并用于为西海岸的跨界绿色蟹管理和传播预测提供信息。最近的工作假设，基因组结构，已越来越多地发现在当地适应中发挥作用，也可能是一个物种在基因流高时快速适应能力的关键。该项目集成了多种方法来跟踪的速度和动态的适应与基因流在一个明确的海洋环境中的温度梯度使用入侵欧洲绿色蟹（Carcinus maenas）。在这个系统中，以前的工作确定了一套基因，似乎构成平衡的多态性，其等位基因频率与站点温度强烈相关，对一个均匀的中性遗传背景。该项目有三个主要目标：1）在一个全面的空间和时间数据集上检查对温度的细尺度选择，该数据集包括西海岸大部分物种的历史，2）跟踪萨利希海不断扩大的范围前沿，将范围边缘的个体的遗传轨迹与扩散的海洋学建模进行比较，和3）表征假定的平衡多态性周围的基因组区域，并在全球复制的群体中检查它们与温度的关联的普遍性。这种结合进化海洋学的方法代表了在高度动态的自然海洋环境中快速适应的速度和性质的前所未有的测试。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Marine invasive species pose a serious and ongoing risk to ocean ecosystems and the economies that rely on them. Understanding how such species adapt rapidly to new environments is key to preventing and managing invasions. Traditionally, the focus has been on inherent traits and flexibility of an invasive species, ignoring the potential for evolutionary change after introduction. However, recent research has shown that some marine species may evolve specific genomic features which allow highly efficient selection over as little as a single generation. This project tests the importance of genomic traits in allowing marine invasive species to survive and thrive on new shores. Its focus is on the high-impact invasive European green crab, which has spread over 1,500 km of the West Coast of North America since 1989 and has very recently begun expanding into the Salish Sea. This project tracks the earliest stages of green crab invasion into a new environment where the species is predicted to have substantial ecological and economic impacts. Genetic differences are followed over time and space across the entire West Coast, with a focus on crabs found in the Salish Sea where the species is currently expanding. Genetic data is complemented by oceanographic modeling to predict the spread of green crabs into the Salish Sea and across the West Coast. Finally, targeted sequencing and prior sampling are used to probe the genomic traits underlying these changes and determine if the same traits have played a role in the species' invasive success on other shores. Sampling for this project is conducted by Washington Sea Grant's Crab Team, an expansive outreach and monitoring program powered largely by hundreds of volunteers who monitor green crabs across 3,000 miles of coastline in the Salish Sea. The results of this project are shared with these volunteers and other stakeholders and is used to inform trans-boundary green crab management and spread prediction on the West Coast.Recent work has hypothesized that genomic architecture, which has been increasingly discovered to play a role in local adaptation, may also be key to a species' ability to adapt quickly when gene flow is high. This project integrates multiple approaches to track the speed and dynamics of adaptation-with-gene flow across a thermal gradient in an explicit oceanographic context using the invasive European green crab (Carcinus maenas). Prior work in this system identified a suite of genes that appear to constitute balanced polymorphisms whose allele frequencies correlate strongly with site temperature against a homogeneous neutral genetic background. This project has three main goals: 1) To examine fine-scale selection to temperature over a comprehensive spatial and temporal data set comprising most of the species' history on the West Coast, 2) To track the expanding range front in the Salish Sea, comparing the genetic trajectory of individuals at the range edge with oceanographic modeling of dispersal, and 3) To characterize the genomic regions surrounding putative balanced polymorphisms and examine the ubiquity of their association with temperature across globally replicated populations. This coupled evolutionary oceanography approach represents an unprecedented test of the speed and nature of rapid adaptation in a highly dynamic natural marine environment.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.