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它们的经济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，研究的重点是入侵物种的内在特征和灵活性，而忽视了入侵物种引入后的进化变化潜力。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一代内进行高效的选择。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。它的重点是高影响力的入侵性欧洲绿蟹，自1989年以来已经在北美西海岸蔓延了1500多公里，最近开始向萨利希海扩张。该项目追踪绿蟹入侵新环境的最早阶段，预计该物种将对新环境产生重大的生态和经济影响。随着时间和空间的推移，整个西海岸的遗传差异得到了关注，重点是在萨利希海发现的螃蟹，该物种目前正在扩大。遗传数据与海洋学模型相辅相成，以预测绿蟹在萨利希海和整个西海岸的传播。最后，利用目标测序和预先取样来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入侵其他海岸的成功中发挥了作用。这个项目的采样是由华盛顿海洋基金的螃蟹小组进行的，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3000英里海岸线上的绿蟹。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境绿蟹管理和传播预测提供信息。最近的研究假设，基因组结构在局部适应中发挥着越来越多的作用，也可能是一个物种在基因流高时快速适应能力的关键。该项目整合了多种方法，利用入侵的欧洲绿蟹（Carcinus maenas）在明确的海洋学背景下，追踪温度梯度下基因适应流的速度和动态。在此系统中，先前的工作确定了一组基因，这些基因似乎构成平衡多态性，其等位基因频率与均匀中性遗传背景下的位点温度密切相关。该项目有三个主要目标：1)利用包含西海岸大部分物种历史的综合时空数据集，研究对温度的精细尺度选择；2)跟踪萨利希海范围前沿的扩展，将范围边缘个体的遗传轨迹与海洋扩散模型进行比较；3)描述假定的平衡多态性周围的基因组区域，并检查它们与全球复制种群中温度的普遍关联。这种相结合的进化海洋学方法是对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考验。该奖项反映了美国国家科学基金会的法定使命，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.