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危险。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，人们把重点放在入侵物种的固有特征和灵活性上，而忽视了引入后进化变化的可能性。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，从而允许在短短一代时间内进行高效的选择。该项目测试了基因组特征在允许海洋入侵物种在新海岸上生存和繁衍方面的重要性。它的重点是高影响力的入侵欧洲青蟹，自1989年以来，这种蟹已经蔓延到北美西海岸1500公里处，最近开始向萨利什海扩张。该项目跟踪青蟹入侵新环境的最早阶段，预计这种物种将对生态和经济产生重大影响。随着时间和空间的推移，整个西海岸都会出现遗传差异，重点是在萨利什海发现的螃蟹，那里的物种目前正在扩大。遗传数据得到海洋学建模的补充，以预测青蟹进入萨利什海和整个西海岸的传播情况。最后，使用定向测序和事先采样来探索这些变化背后的基因组特征，并确定相同的特征是否在该物种在其他海岸的入侵成功中发挥了作用。这个项目的抽样工作是由华盛顿海格兰特的螃蟹团队进行的，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支持，他们监测萨利什海3000英里海岸线上的青蟹。该项目的结果将与这些志愿者和其他利益相关者分享，并用于为跨境青蟹管理和西海岸传播预测提供信息。最近的研究假设，越来越多的人发现基因组结构在局部适应中发挥作用，这可能也是一个物种在基因流动高时快速适应能力的关键。该项目综合了多种方法，利用入侵的欧洲青蟹(Carcinus Maenas)，在明确的海洋环境中跟踪适应基因在温度梯度上流动的速度和动态。该系统以前的工作确定了一组似乎构成平衡多态的基因，这些基因的等位基因频率与同质中性遗传背景下的部位温度密切相关。该项目有三个主要目标：1)在包括西海岸大部分物种历史的综合时空数据集上检查对温度的精细选择；2)跟踪Salish海的范围前沿扩大，将范围边缘的个体的遗传轨迹与扩散的海洋学模型进行比较；3)描述假定的平衡多态周围的基因组区域，并检查它们与温度在全球复制种群中的普遍存在。这一结合的进化海洋学方法代表着对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考验。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.