Placing the Floridian Genetic Break for Nearshore Taxa into a Regional Phylogenetic Perspective Using Three Lineages of Marine Mussels

利用海洋贻贝的三个谱系将佛罗里达近岸类群的遗传断裂纳入区域系统发育视角

• 批准号: 0099084
• 负责人: Diarmaid O'Foighil
• 金额: $ 33.85万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-15 至 2004-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0099084&HistoricalAwards=false
• 关键词: Placing; Floridian; Genetic; Break; Nearshore

Understanding spatio-temporal patterns of biotic diversity represents one of the central challenges facing ecologists and systernatists. This challenge is particularly acute in the marine environment where we are only just now beginning to comprehend the evolutionary processes which have produced the epic diversity evident in tropical nearshore faunas. A central paradox in marine evolution is how speciation rates in many clades are sufficiently high to produce large sibling species complexes on geographic scales that are dwarfed by the dispersal potential of their planktonic larval stages. The aim of this project is to address how the Gulf-Atlantic genetic disjunction for regionally distributed Caribbean morphospecies scales relative to the genetic structuring experienced over the rest of their collective geographic ranges. Three distinct phylogenetic trajectories are hypothesized that hinge on whether the Gulf--Atlantic genetic disjunction for individual study taxa originated early in the history of the Miocene Suwannee Seaway, or postdated it's Pliocene closure, and whether or not genetic cohesiveness has been maintained across oceanic barriers to dispersal. These hypotheses will be tested using three exemplar mytilid morphospecies chosen on the basis of their appropriate geographic ranges, ecological abundance in distinct coastal habitats, availability of reference congeners on the Pacific side of the isthmus of Panama, and possession of rapidly evolving paternally -transmitted mitochondrial lineages. Mitochondrial and nuclear gene trees will be generated for population samples spanning the southeastern Florida genetic break, the oceanic dispersal barrier to Bermuda, and representative locations in the Caribbean Basin. Sampling of Caribbean/eastern Pacific congeners will allow the identification of transisthmian reference geminate species and provide a meaningful temporal perspective for the intraspecific gene tree topologies. The project promises to yield important new insights into the nature and origin of biotic diversity in both this regional fauna and in the broader marine environment.

了解生物多样性的时空模式是生态学家和系统学家面临的主要挑战之一。这一挑战在海洋环境中尤为严峻，我们现在才刚刚开始理解产生热带近岸动物群中明显的史诗多样性的进化过程。海洋进化的一个中心悖论是，许多分支的物种形成率足够高，足以在地理尺度上产生大型的兄弟物种复合体，而这些复合体与浮游幼虫阶段的扩散潜力相比相形见绌。 该项目的目的是解决区域分布的加勒比形态种规模的海湾-大西洋遗传分离与其他集体地理范围内经历的遗传结构的关系。假设了三种不同的系统发育轨迹，这些轨迹取决于个体研究类群的海湾-大西洋遗传分离是否起源于中新世苏旺尼海道的历史早期，或者晚于其上新世关闭，以及是否跨越海洋障碍保持了遗传凝聚力驱散。这些假设将使用三种典型的贻贝形态种进行测试，这些形态种是根据其适当的地理范围、不同沿海生境的生态丰度、巴拿马地峡太平洋一侧参考同系物的可用性以及拥有快速进化的父系遗传线粒体而选择的。血统。将为跨越佛罗里达州东南部遗传断裂、百慕大海洋传播障碍以及加勒比海盆地代表性地点的种群样本生成线粒体和核基因树。对加勒比/东太平洋同系物进行采样将能够识别跨峡参考双生物种，并为种内基因树拓扑提供有意义的时间视角。该项目有望为该区域动物群和更广泛的海洋环境中生物多样性的性质和起源提供重要的新见解。