Collaborative Research: Patterns of Larval Dispersal and Postsettlement Selection Shaping Connectivity of Oyster Populations Along an Ecotone

合作研究：幼体扩散和定居后选择的模式塑造生态交错带沿线牡蛎种群的连通性

• 批准号: 0830547
• 负责人: Matthew Hare
• 金额: $ 79.31万
• 依托单位: Cornell Univ - State: AWDS MADE PRIOR MAY 2010
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-13 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0830547&HistoricalAwards=false
• 关键词: Collaborative; Research; Patterns; Larval; Dispersal

Population persistence and the scale of local adaptation are determined by both larval connectivity and post-settlement selection when habitats are spatially heterogeneous for growth and/or reproduction. Unfortunately, the relative importance of factors acting before and after settlement that limit recruitment and gene flow is still unknown for most species and most marine ecosystems. This is partly because the interactions between larval behavior and hydrography are difficult to study, so dispersal constraints are only inferred indirectly. In addition, many marine species are not amenable to strong spatial tests of post-settlement selection and these experiments are difficult to accomplish at the large spatial scales relevant to high dispersal species. Consequently, only a handful of natural systems have yielded results that distinguish pre- and post-settlement constraints on gene flow such that our understanding of mechanisms generating genetic and phenotypic population structure is piece meal. The intellectual merit of the study is that it achieves this dual goal in an estuarine species inhabiting semi-connected lagoons along eastern Florida where there is a latitudinal gradient in environmental variables, community composition, and potential larval dispersal vectors. Much of the western North Atlantic coastline includes shallow lagoons enclosed by barrier islands, but only a handful of studies have measured connectivity among estuaries, and none among lagoons. This project builds on significant previous research on the eastern oyster, Crassostrea Virginica to integrate pre- and post-settlement measurements. High resolution genetic identification of migrants will be used to construct a connectivity matrix among 30 populations in each of three years. Statistical associations will be tested between dispersal patterns and hypothesized dispersal vectors and constraints. Cohort analysis will be used to test for spatial variation in genotype-specific survivorship along the entire coast. Also, in each of two years, relative postsettlement survivorship and performance will be measured in field common gardens in which local individuals, migrants and hybrids are compared. Finally, fertilization efficiency of within- and between-population crosses will be compared to test the hypothesis that gamete incompatibilities limit gene flow. The results will be integrated in models that describe the spatially and/or temporally dynamic balance between dispersal and selection, define the spatial scale of local adaptation along the ecotone, and identify abiotic gene flow constraints that may affect codistributed species.The broader impacts of this study derive from its focus on important habitats for diversity and fisheries management, and on the involvement of underrepresented groups. The oyster populations under study inhabit eastern Florida lagoons that possess the highest diversity of any estuary in the United States, yet this coastline is undergoing rapid development. In addition, the Cape Canaveral lagoons contain the oldest marine protected area in North America. Understanding the impact of this reserve on surrounding fished populations hinges on dispersal across its boundaries and on habitat quality, both of which are studied here. This study will also support one PhD student who will focus on the measurements of selection for her dissertation. The graduate student is a female African-American who endeavors to study marine evolutionary ecology, a goal spanning two fields with extremely low minority representation. The P.I. has a continuing interest in attracting the next generation of scholars. Currently four undergraduates work in the Hare lab on projects related to the Florida ecotone. Three of the undergraduates are women and the fourth an African-American. Funding from NSF will allow undergraduate participation to be expanded to include summer field work in Florida. Previous undergraduates working in the Hare lab have obtained Howard Hughes fellowships and contributed to publications (Gaines et al. 2005). The University of Maryland graduates more African-Americans than any of the top 20 universities in this country. This provides a large pool of minority candidates for possible recruitment to the Hare lab. The P.I. has a history of integrating primary research results into lectures in introductory genetics. Research results are also disseminated via lab web page postings.

种群的持久性和当地适应的规模是由幼虫的连接和定居后的选择时，栖息地是空间异质性的增长和/或繁殖。不幸的是，对大多数物种和大多数海洋生态系统而言，在定居之前和之后限制补充和基因流动的因素的相对重要性仍然未知。这部分是因为幼虫的行为和水文之间的相互作用很难研究，所以扩散的限制只能间接推断。此外，许多海洋物种不适合强大的空间测试后解决的选择，这些实验是很难完成的大空间尺度相关的高分散物种。因此，只有少数自然系统产生的结果，区分前和后定居的基因流的限制，使我们的理解机制产生遗传和表型的人口结构是零碎的。这项研究的智力价值是，它实现了这一双重目标，在一个河口物种栖息在半连接泻湖沿着佛罗里达州东部，那里有一个纬度梯度的环境变量，社区组成，和潜在的幼虫传播媒介。北大西洋西部的大部分海岸线包括由屏障岛屿包围的浅泻湖，但只有少数研究测量了河口之间的连通性，而泻湖之间则没有。该项目建立在以前对东部牡蛎Crassostrea Virginica的重要研究的基础上，以整合沉降前和沉降后的测量。高分辨率的移民遗传鉴定将被用来构建一个连接矩阵之间的30个人口在每三年。将测试扩散模式和假设的扩散矢量和约束之间的统计关联。队列分析将用于检验沿着整个海岸的基因型特异性存活率的空间变异。此外，在两年的每一年，相对定居后的生存和性能将在外地共同花园，其中比较当地的个人，移民和杂交。最后，将比较种群内和种群间杂交的受精效率，以检验配子不相容性限制基因流动的假设。结果将被集成在模型中，描述的空间和/或时间之间的动态平衡的扩散和选择，定义的空间尺度的本地适应沿着的生态交错带，并确定非生物基因流的限制，可能会影响codistributed species.The更广泛的影响，这项研究的重点来自重要的栖息地的多样性和渔业管理，并参与代表性不足的群体。研究中的牡蛎种群栖息在佛罗里达东部的泻湖中，这些泻湖拥有美国任何河口最高的多样性，但这条海岸线正在迅速发展。此外，卡纳维拉尔角泻湖拥有北美最古老的海洋保护区。了解这个保护区对周围鱼类种群的影响取决于其边界的扩散和栖息地质量，这两个都在这里进行了研究。这项研究也将支持一个博士生谁将专注于她的论文选择的测量。这名研究生是一名女性非裔美国人，致力于研究海洋进化生态学，其目标跨越两个领域，少数族裔代表性极低。私家侦探一直致力于吸引下一代学者。目前，四名本科生在野兔实验室从事与佛罗里达生态交错带有关的项目。其中三名本科生是女性，第四名是非洲裔美国人。来自NSF的资金将允许本科生的参与扩大到包括在佛罗里达的夏季实地考察。以前在Hare实验室工作的本科生获得了霍华德休斯奖学金，并为出版物做出了贡献（Gaines et al. 2005）。马里兰州大学的非裔美国人毕业生比这个国家排名前20位的任何一所大学都多。这为Hare实验室的可能招聘提供了大量的少数族裔候选人。私家侦探有将主要研究成果融入遗传学导论讲座的历史。研究结果也通过实验室网页发布。