Collaborative Research: Have transantarctic dispersal corridors impacted Antarctic marine biodiversity?

合作研究：跨南极扩散走廊是否影响了南极海洋生物多样性？

• 批准号: 1916665
• 负责人: Andrew Mahon
• 金额: $ 49.96万
• 依托单位: Central Michigan University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1916665&HistoricalAwards=false
• 关键词: Collaborative; Research; transantarctic; dispersal; corridors

Antarctica is among the most rapidly warming places on the planet, and some reports suggest the Antarctic environment is approaching, or possibly beyond, the tipping point for ice shelf collapse. The loss of ice around Antarctica is dramatically changing habitat availability for marine fauna, particularly benthic marine invertebrate species. Building on past studies, this research will provide insights into how changing climate impacts species distribution and community structure. Geological data suggests that during periods when ice extent was much reduced relative to modern levels, marine seaways connected the Ross and Weddell Seas on either side of Antarctica. However, most theories about the origins of current marine invertebrate distribution patterns fail to consider this transantarctic connection. This research will use molecular genomic tools to probe the DNA of Antarctic marine invertebrates and explore alternative hypotheses about factors that may have shaped current patterns of animal biodiversity in the Southern Ocean. Research will inform predictions about how species distributions may change as Antarctic ice sheets continue to deteriorate and provide critical information on how organisms adjust their ranges in response to environmental change. This work includes several specific outreach activities including presentations in K-8 classrooms, several short-format videos on Antarctic genomics and field work, and two 3-day workshops on bioinformatics approaches. A minimum of 4 graduate students, a postdoc and several undergraduates will also be trained during this project.The overarching goal of this research is to understand environmental factors that have shaped patterns of present-day diversity in Antarctic benthic marine invertebrates. Evidence from sediment cores and modeling suggests ice shelf collapses have occurred multiple times in the last few million years. During these periods, transantarctic seaways connected the Ross and Weddell Seas. This research will assess whether the presence of transantarctic waterways helps explain observed similarities between the Ross and Weddell Seas benthic marine invertebrate fauna better than other current hypotheses (e.g., dispersal by the Antarctic Circumpolar Current, or expansion from common glacial refugia). Seven Antarctic benthic invertebrate taxa will be targeted to test alternative hypothesis about the origins of population genetic structure in the Southern Ocean using Single Nucleotide Polymorphism (SNP) markers that sample thousands of loci across the genome. Additionally, research will test the current paradigm that divergence between closely related, often cryptic, species is the result of population bottlenecks caused by glaciation. Specifically, SNP data will be mapped on to draft genomes of three of our target taxa to assess the degree of genetic divergence and look for signs of selection. Research findings may be applicable to other marine ecosystems around the planet.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.

南极是地球上最快速变暖的地方之一，一些报道表明，南极环境即将接近或可能超出冰架倒塌的转折点。南极周围的冰损失正在大大改变海洋动物群，尤其是底栖海洋无脊椎动物的栖息地。在过去的研究基础上，这项研究将提供有关气候变化如何影响物种分布和社区结构的见解。地质数据表明，在相对于现代水平大大降低的时期，海道将罗斯和韦德尔在南极两侧连接起来。但是，关于当前海洋无脊椎动物分布模式的起源的大多数理论都无法考虑这种跨抗性连接。这项研究将使用分子基因组工具来探测南极海洋无脊椎动物的DNA，并探讨有关可能影响南方大洋动物生物多样性模式的因素的替代假设。研究将为您的预测提供有关物种分布如何变化的预测，因为南极冰盖继续恶化，并提供有关生物如何调整其范围以响应环境变化的关键信息。这项工作包括一些特定的外展活动，包括在K-8教室中的演讲，几个有关南极基因组学和现场工作的简短视频，以及有关生物信息学方法的两个为期3天的3天研讨会。在此项目中，至少有4名研究生，一个博士后和几名本科生也将接受培训。这项研究的总体目标是了解已经塑造了南极底栖海洋无脊椎动物的当今多样性模式的环境因素。沉积物核心和建模的证据表明，在过去的几百万年中，冰架崩溃了多次。在这些时期，跨北极海道连接了罗斯和韦德尔海。这项研究将评估跨二行式水道的存在是否有助于解释罗斯和韦德尔海域底栖海洋无脊椎动物动物区系之间的相似之处，而不是其他当前假设（例如，南极近极极性电流分散，或与普通冰川雷克利亚的扩展相似）。使用单核苷酸多态性（SNP）标记，将七个南极无脊椎动物分类群的目标用于检验有关南大洋种群遗传结构的起源的替代假设，这些标志物在整个基因组中进行了数千个基因座。此外，研究将测试当前的范式，即密切相关（通常隐性物种）之间的差异是冰川造成的种群瓶颈的结果。具体而言，SNP数据将被映射到我们的三个目标分类单元的基因组中，以评估遗传差异的程度并寻找选择的迹象。研究结果可能适用于地球周围的其他海洋生态系统。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估来获得支持。