COLLABORATIVE RESEARCH: Ecological and evolutionary dynamics of secondary contact

通过拆除水坝，全国各地的河流和小溪正在恢复其原有的流动模式，其中许多水坝是几个世纪前建造的，为构成殖民地经济基础的小型米尔斯提供能源。该项目利用计划中的大坝拆除，将连接已经分离了近四个世纪的鱼类种群，以研究这些最近不同的鱼类种群之间的二次接触的生态和进化后果，这些鱼类种群可能会杂交，但也可能会竞争。这项工作的成果将有助于养护和管理洄游的灰腰琵琶鱼，这是沿海淡水和海洋生境的一种重要资源，也是大力恢复和养护工作的重点。研究人员将与国家管理人员，康涅狄格州能源和环境保护部，湖泊协会和土地信托合作，以确定恢复迁移人口的后果，提供对alewife恢复至关重要的信息，并教育当地社区河流恢复的后果。该项目将培养一名博士后研究员，沿着研究生和本科生参加一个跨学科项目，该项目依赖于先进的遗传学技术、实地取样以及操纵性实地和实验室实验。耶鲁大学现有的一个项目将支持代表性不足的少数民族本科生参与暑期研究。培训将包括研究的更广泛的科学背景，研究方法，数据分析，书面和口头项目报告，并与公众直接参与，以展示研究的社会效益。本项目利用全湖恢复项目来了解最近分歧的alewife谱系之间的二次接触的生态和进化动力学。水坝的建造导致了两种不同的灰蝶生活史形式：在湖泊和沿海海洋之间移动的祖先溯河产卵形式和居住在湖泊中的内陆形式。该项目将结合联合收割机先进的基因组学，小规模的实验，和全湖的观察和实验，以记录和了解二次接触的后果，当大坝拆除允许溯河产卵的alewife重新引入湖泊，包含内陆锁定的形式。与拆除大坝的国家机构密切合作，将使调查人员能够从一开始就研究二次接触。该项目解决了三个阶段，以应对二次接触：快速生态变化的浮游生物群落和营养流，快速进化的反应，在无脊椎动物种群在新的生态条件下，和两个alewife变形之间的相互作用，可能会导致杂交，并在较长的时间内，alewife进化和当地的适应。第一种反应--湖泊群落的生态变化--对于解释由此产生的进化变化至关重要。该项目的独特之处在于它能够捕捉到两个时间尺度上的二次接触的后果。结果将提供罕见的深入了解生态和进化过程之间的反馈，在现场人口的重要影响，生态系统功能和恢复生态系统中的生物多样性的维护与二次接触。

Rivers and streams across the country are being restored to their original flow patterns by the removal of dams, many of which were constructed centuries ago to provide energy for small mills that formed the basis of colonial economies. This project takes advantage of planned dam removals that will connect fish populations that have been separated for nearly four centuries, in order to study the ecological and evolutionary consequences of secondary contact between these recently divergent fish populations, which may interbreed but also may compete. Results from this work will contribute to the conservation and management of migratory alewife fish, a critical resource in coastal freshwater and marine habitats and the focus of intensive restoration and conservation efforts. Researchers will work collaboratively with state managers, the Connecticut Department of Energy and Environmental Protection, lake associations, and land trusts to determine the consequences of restoring migratory populations, provide information vital to alewife recovery, and educate local communities on the consequences of river restoration. The project will train a postdoctoral researcher along with graduate and undergraduate students in an interdisciplinary project that relies on advanced genetics techniques, field sampling, and manipulative field and laboratory experiments. An existing program at Yale University will support involvement of underrepresented minority undergraduate students in summer research. Training will include the broader scientific context of the research, research methods, data analysis, written and oral project reports, and direct involvement with the public to present the societal benefits of the research. This project takes advantage of whole-lake restoration projects to understand the ecological and evolutionary dynamics of secondary contact between recently diverged lineages of alewife. Isolation caused by construction of dams has resulted in 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. This project will combine advanced genomics, small-scale experiments, and whole-lake observations and experiments to document and understand the consequences of secondary contact, when dam removal allows reintroduction of anadromous alewife into lakes that contain the land-locked form. Close collaboration with the state agency that removes dams will allow the investigators to study secondary contact from its initiation. The project addresses three stages in response to secondary contact: rapid ecological change in planktonic communities and nutrient flux, rapid evolutionary responses in invertebrate populations in response to novel ecological conditions, and interactions between the two alewife morphs that may result in hybridization and, over the longer-term, alewife evolution and local adaptation. The first of these responses - ecological changes in lacustrine communities - is essential in order to interpret the evolutionary changes that result. The project is unique in its ability to capture the consequences of secondary contact on both time scales. Results will provide rare insight into feedbacks between ecological and evolutionary processes in field populations following secondary contact with important implications for ecosystem function and the maintenance of biodiversity in restored ecosystems.