Dispersal, connectivity and local adaptation along an extreme environmental gradient

预计未来海水温度的上升将对海洋生物产生深远和有害的后果。生物体必须迁移到更有利的环境中，适应以保持体内平衡，或者通过基因组变化适应新的热状态，否则将发生局部灭绝。对于基本上完全定居的海洋底栖生物而言，它们的迁移能力取决于幼虫的扩散，而据推测，这种扩散在变暖条件下受到限制。在这个项目中，研究小组研究了四种海洋无脊椎动物物种（珊瑚，海胆，牡蛎，海鞘）的种群，这些物种跨越沿着阿拉伯半岛东北部的巨大温度梯度，作为一个自然系统，以量化温度升高对扩散，遗传连接和适应的影响。该团队将使用一种综合方法，包括实验性幼虫测定、生物物理建模和高通量测序技术。这项研究全面评估了气候变化对经济和生态重要生物的潜在影响，同时丰富了对核心生态和进化概念的理解。这一项目的成功是与阿拉伯联合酋长国阿布扎比的纽约大学进行协同国际合作的结果。该研究项目为一名博士后学者，一名研究生和四名本科生提供指导和培训，这些学生来自代表性不足的少数群体，他们有兴趣接受研究生教育。这些学者中的每一个都可以获得前沿科学，国际和合作研究的机会，并将他们的科学传播给不同的受众。此外，更广泛的影响延伸到夏洛特社区和更广泛的公众在这一地区的北卡罗来纳州通过执行两个推广展览在当地的科学博物馆，了解扩散，遗传连接和适应之间的相互作用将是关键，预测未来的海洋温度上升对海洋底栖无脊椎动物的影响。该项目利用波斯湾/阿拉伯湾世界上最温暖的珊瑚礁作为模型系统，研究温度升高对这些生态和进化重要过程的影响，这些珊瑚礁目前的温度是下世纪其他地方珊瑚礁所没有的。四个无脊椎动物物种的波斯/阿拉伯湾的人口相比，在邻近的阿曼湾，经历了一个更良性的热环境的人口。第一个目标的特点的生存，远洋持续时间，从不同的人口的四个焦点种沿着热梯度的幼虫定居的影响，温度升高。这些结果还比较了潜在的变化，从每个位置的女性在鸡蛋投资策略。第二个目标是使用这些种群特异性的反应，从幼虫实验中收集到的参数化模型，现在和未来的扩散，并将它们与现有的遗传连接模式进行比较。最后的目标分析了这些人群的热适应的基因组基础，通过全基因组比较和单代选择实验相结合，以确定是否有证据表明，在分类学上不同的无脊椎动物物种的趋同/平行进化。该项目旨在通过对温度对生命周期关键阶段的影响提供新的见解，并阐明海洋无脊椎动物热适应的基因组过程，从而推进我们对气候变化适应性的认识。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。

Future increases in sea temperatures are expected to have far-reaching and detrimental consequences for marine organisms. Organisms must either move to more favorable environments, acclimate to maintain homeostasis, or adapt through genomic changes to the new thermal regime, otherwise local extinction will occur. For marine benthic organisms that are largely and completely sedentary, their capacity to migrate is dependent on larval dispersal, which is hypothesized to be limited under warming conditions. In this project, the research team studies populations of four marine invertebrate species (coral, sea urchin, oyster, ascidian) across the substantial thermal gradient along the northeastern Arabian Peninsula as a natural system to quantify the effects of elevated temperatures on dispersal, genetic connectivity and adaptation. The team will use an integrative approach that consists of experimental larval assays, biophysical modeling and high throughput sequencing technologies. This study provides a comprehensive assessment of the potential impacts of climate change on economically and ecologically important organisms, while enriching the understanding of core ecological and evolutionary concepts. The success of this project results from a synergistic international collaboration with New York University at Abu Dhabi, United Arab Emirates. This research project provides mentoring and training for a postdoctoral scholar, a graduate student, and four undergraduate students from underrepresented minority groups who are interested in pursuing graduate education. Each of these scholars is provided access to cutting-edge science, international and collaborative research opportunities, and experience disseminating their science to different audiences. Furthermore, the broader impacts extend to the Charlotte community and wider public in this region of North Carolina through the implementation of two outreach exhibits at a local science museum.Understanding the interplay between dispersal, genetic connectivity and adaptation will be key to forecasting the impacts on future sea temperature increases on marine benthic invertebrates. This project uses the world's warmest reefs in the Persian/Arabian Gulf, that currently experience temperatures not anticipated on reefs elsewhere within the next century, as a model system to study the effects of elevated temperatures on these ecologically and evolutionary important processes. Populations of four invertebrate species from the Persian/Arabian Gulf are compared to populations in the neighboring Gulf of Oman that experiences a more benign thermal environment. The first aim characterizes the impact of elevated temperatures on the survival, pelagic duration, and settlement responses of larvae from different populations of the four focal species along the thermal gradient. These results are additionally compared with potential shifts in egg investment strategies by females from each location. The second aim uses these population-specific responses gleaned from the larval experiments to parameterize models of present day and future dispersal and compares them against existing patterns of genetic connectivity. The final aim analyzes the genomic basis for thermal adaptation in these populations through a combination of whole genome comparisons and single-generation selection experiments, with the goal to ascertain whether there is evidence for convergent/parallel evolution in the taxonomically distinct invertebrate species. This project is expected to advance our knowledge of adaptation to climate change by providing new insights into the impacts of temperature on a key life cycle stage and elucidate the genomic processes governing thermal adaptation in marine invertebrates.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.