COLLABORATIVE RESEARCH: LTREB: Long-term ecological and evolutionary dynamics of secondary contact

合作研究：LTREB：二次接触的长期生态和进化动力学

• 批准号: 2102763
• 负责人: Eric Palkovacs
• 金额: $ 17.96万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-15 至 2026-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2102763&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; LTREB; Long; term

Populations of animals and plants are regularly isolated by natural processes and human activities. In isolation, populations adapt to local environments, and traits and genes may diverge. This adaptive divergence can create ecologically important variation that changes the role of species within ecosystems. Natural processes and human activities can also allow or force populations that have diverged in isolation to come back into contact - a process called secondary contact. The outcome of secondary contact is important for understanding how populations evolve and ecosystems function. This LTREB takes advantage of a whole-lake restoration project to study the decade-scale ecological and evolutionary dynamics of secondary contact between recently diverged lineages of alewife. Alewife are a well-studied and ecologically important fish found in lakes and in the coastal ocean of eastern North America. There are two divergent alewife life-history forms: the ancestral anadromous form that moves between lakes and the coastal ocean and a landlocked form that is resident in lakes. Many landlocked populations were formed by the construction of dams by colonial Americans. The recent removal of dams and construction of fishways create opportunities for secondary contact between landlocked and anadromous alewife populations. Findings will address questions fundamental to the generation and maintenance of biodiversity, the ecological impact of variation within species, and the impacts of human accelerated environmental changes including population fragmentation, restoration of habitat connectivity, and climate change. This project will inform the conservation and management of anadromous alewife, a critical resource in coastal freshwater and marine habitats, a species of conservation concern, and the focus of intensive restoration and conservation efforts. The genomic tools developed by this project will help resource managers address important questions, such as the impact of bycatch on anadromous alewife populations. The project will train graduate and undergraduate students, including students from underrepresented backgrounds, in a unique combination of advanced genomics techniques and whole-lake sampling. This project asks how climate change, anadromous alewife population recovery, and periodic major hybridization events (2-3 per decade), interact to determine the magnitude of hybridization and direction of gene flow, phenotypic differentiation among alewife forms, and whole-lake impacts. It focuses on the restoration of Rogers Lake, Connecticut and regional reference lakes. This project utilizes highly informative microhaplotype genetic markers to measure hybridization and gene flow; measures trophic morphology, individual growth rates, diets, and habitat use to assess phenotypic and ecological differentiation among forms; and samples inorganic nutrients, phytoplankton, and zooplankton to evaluate whole-lake impacts. This research provides a rare opportunity to track the ecological and evolutionary dynamics from the initiation of secondary contact, and the long-term research plan facilitates the detection of rare events and interactions between ecological and evolutionary process at the whole ecosystem scale.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.

由于自然过程和人类活动，动植物种群经常被隔离。在孤立状态下，种群适应当地环境，性状和基因可能出现分化。这种适应性差异可以产生重要的生态变异，从而改变物种在生态系统中的作用。自然过程和人类活动也可以允许或迫使孤立分离的种群重新接触，这一过程称为二次接触。二次接触的结果对于了解种群的进化和生态系统的功能非常重要。本研究利用全湖恢复项目，研究了大灰鲟新近分化谱系间继发接触的十年尺度生态和进化动态。大灰鲱是一种被充分研究过的重要的生态鱼类，发现于北美东部的湖泊和沿海海域。有两种不同的alewife生活史形式：在湖泊和沿海海洋之间移动的祖先溯河形式和居住在湖泊中的内陆形式。许多内陆人口是由殖民时期的美国人修建水坝形成的。最近水坝的拆除和鱼道的建设为内陆和海中灰西鲱种群之间的二次接触创造了机会。研究结果将解决生物多样性的产生和维持、物种变异的生态影响、人类加速环境变化的影响（包括种群破碎化、栖息地连通性恢复和气候变化）等基本问题。这一项目将为雌雄同体大灰鲱的养护和管理提供信息，雌雄同体大灰鲱是沿海淡水和海洋生境的重要资源，是养护关注的物种，也是加强恢复和养护工作的重点。该项目开发的基因组工具将帮助资源管理者解决重要问题，例如副渔获物对溯河大灰鲭鱼种群的影响。该项目将培训研究生和本科生，包括来自代表性不足背景的学生，将先进的基因组学技术和全湖采样进行独特的结合。该项目探讨气候变化、溯河大灰鲑种群恢复和周期性重大杂交事件（每十年2-3次）如何相互作用，以确定杂交的规模和基因流动的方向、大灰鲑种类之间的表型分化以及对整个湖泊的影响。它侧重于罗杰斯湖，康涅狄格州和区域参考湖泊的恢复。该项目利用高信息量的微单倍型遗传标记来测量杂交和基因流动；测量营养形态、个体生长速率、饮食和栖息地利用，以评估各种形态之间的表型和生态分化；并对无机营养物、浮游植物和浮游动物进行取样，以评估整个湖泊的影响。该研究为从次生接触开始追踪生态演化动态提供了难得的机会，并为在整个生态系统尺度上发现生态与演化过程之间的罕见事件和相互作用提供了长期研究计划。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。

项目成果

The Evolutionary Consequences of Dams and Other Barriers for Riverine Fishes

水坝和其他屏障对河流鱼类的进化后果

• DOI: 10.1093/biosci/biac004
• 发表时间: 2022
• 期刊: BioScience
• 影响因子: 10.1
• 作者: Zarri, Liam J.;Palkovacs, Eric P.;Post, David M.;Therkildsen, Nina O.;Flecker, Alexander S.
• 通讯作者: Flecker, Alexander S.