Community Phylogeny and Global Phylogeography of the Neuston

“这个奖项是根据2009年美国复苏和再投资法案(公法111-5)资助的。”这个项目旨在构建第一个海洋群落系统发育。它的灵感来自于现代生物多样性概念的核心--综合视角。这种整合的经验实现要求研究系统足够简单，易于处理，但(理想情况下)包含引人注目的生态和进化现象。目标海洋社区纽斯顿在很大程度上体现了这些特征。它由数量相对较少的相互作用的物种组成，这些物种漂浮在地球副热带环流(占海洋表面积的40%)的水/大气界面上，在公海上层食物网中发挥着重要作用。Neuston群落的生态基础是一种内共生，涉及软骨鱼寄主(门螺科)及其甲藻光生共生体。软骨磷被各种捕食者捕食，其中最主要的是两个高度专门化的腹足类(腹足科和灰腹足亚科)。除了它的寄居昆虫属Halobates外，人们对这个著名的开阔海洋群落的研究一直很少。研究人员的目标是完成三个营养级别(光共生生物、软骨虫宿主、捕食性腹足类)和所有5个亚热带环流系统的Neuston分类群的综合系统发育/系统地理。群落系统发育部分的两个主要目标是确定光共生的进化起源，以及建立两个腹足类谱系的底栖姐妹谱系，以确定与从底栖生物到纽斯顿的祖先生态转变相关的突触形态变化。系统地理部分的主要目的是建立目标中性类群的物种形成的空间尺度，并检验关于种内遗传结构的三个假说：全球泛混合、洋盆泛混合和环泛混合。这位研究人员开发了一种多方面的采样策略，涉及多个环流系统中的浮游鱼类研究同事、两个海岸的远洋轮船和伍兹霍尔海上学期项目的学生、国家和国际博物馆收藏，以及一个非正式的全球同事网络，将对自发的纽斯顿搁浅事件进行采样。他还与研究蛇形纲、裸目、后腹足类和表位类多样性的同事建立了合作关系，他们将在纽斯顿和腹足类各自的种群以及底栖姐妹血统方面与他密切合作。到目前为止，来自5个环流中的3个环流的初步样本已经产生了结果，不仅证明了主要项目目标的可行性，而且提供了令人兴奋的初步洞察，了解光共生协会的一般性、假定的中生腹足类底栖生物姐妹谱系、可能存在的隐蔽物种复合体以及姐妹类群展示的环间和盆地间遗传结构的不同模式。该项目有一个异常广泛的学生外展部分，以100名海洋教育协会(SEA)本科生和高中生的形式，将参加即将到来的多个SSV Seamans和Amp；SSV Cramer邮轮，谁将收集Neuston分类群。研究人员将在实地向海洋课程提供详细的电子反馈，以便学生能够将他们收集的生物与正在测试的生物地理和进化假说联系起来，并自行确定现有数据拒绝或证实哪些假说。一名研究生和三名UM本科生将在该项目期间接受深入培训。这位名叫西莉亚·丘吉尔的研究生参与了纽斯顿的离岸采样，生成了大量初步数据，最近在她的第一次科学会议上提交了报告。她将与P.I.一起工作/培训，还将与4名专家合作者一起工作/培训，直接在他们的实验室为其中2人培训。密歇根大学的一名本科生已经直接参与了这个项目，调查员将至少再招聘两名。计划在研究专业之间开展大量的国际推广和合作活动，特别是让在不同环流系统工作的浮游鱼类同事以及国际博物馆同事参与。这项研究有望大大加强对巨大的亚热带旋涡表面生态系统的背景知识，目前，即使在大洋中部，也受到不可生物降解的塑料漂浮物逐渐积累的严重影响。这是一个刚刚进入公众讨论的重大新海洋保护问题，例如，参见大众媒体最近对北太平洋巨型垃圾带的描述。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."This project aims to construct the first marine community phylogeny. It is inspired by the integrative perspective that lies at the core of the modern concept of biodiversity. Empirical realization of this integration requires that study systems be simple enough to be tractable, yet (ideally) contain compelling ecological and evolutionary phenomena. The target marine community, the neuston, embodies these characteristics to an exceptional degree. It consists of a relatively small number of interacting species that drift at the water/atmosphere interface of the planet's subtropical gyres (40% of oceanic surface area) and play an important role in open-ocean epipelagic food webs. The ecological base of the neuston community is an endosymbiosis involving chondrophore cnidarian hosts (Porpitidae) and their dinoflagellate photosymbionts. Chondrophores are preyed upon by a variety of predators, chief among them two lineages of highly specialized gastropods (Janthinidae and Glaucinae). This prominent open ocean community has been poorly studied, apart from its resident insect genus Halobates. The investigator aims to complete a combined phylogeny/phylogeography of neuston taxa across three trophic levels (photosymbionts, chondrophore hosts, predatory gastropods) and all 5 subtropical gyre systems. The two main goals of the community phylogeny section are to determine the evolutionary origins of the photosymbiosis, and to establish the benthic sister lineages of both gastropod lineages in order to identify the synapomorphic changes associated with ancestral ecological transitions from benthos to neuston. The primary aims of the phylogeographic section are to establish the spatial scale of speciation for the target neustonic taxa, and to test three hypotheses of within-species genetic structuring: global panmixis; ocean basin panmixis; within gyre panmixis. The investigator has developed a multi-faceted sampling strategy that involves ichthyoplankton research colleagues in multiple gyres systems, the bi-coastal, ocean-going ships and students of the Woods Hole Semester at Sea program, national and international museum collections, and an informal network of colleagues worldwide that will sample spontaneous neuston stranding event. He has also established collaborative relationships with colleagues expert in cnidarian, nudibranch, caenogastropod and epitoniid diversity, who will work closely with him on their respective groups within the neuston and, for gastropods, also within benthic sister lineages. To-date, preliminary samples from 3 of the 5 gyres have yielded results that not only demonstrate the feasibility of the primary project goals, but also provide exciting initial insights into the generality of the photosymbiotic association, the putative benthic sister lineages of neustonic gastropods, the likely presence of cryptic species complexes, and the divergent patterns of among-gyre and among-basin genetic structuring exhibited by sister taxa.This project has an unusually extensive student outreach component in the form of the 100 Sea Education Association (SEA) undergraduates and high school students that will participate in multiple upcoming SSV Seamans & SSV Cramer cruises and who will collect neuston taxa. The investigator will provide detailed electronic feedback to the SEA courses, in the field, so that students will be able to connect the organisms they collect with the biogeographic and evolutionary hypotheses being testing, and to determine for themselves which hypotheses the available data reject, or corroborate. One graduate and three undergraduate UM students will receive in-depth training during this project. The graduate student, Celia Churchill, has participated in offshore neuston sampling, generated much of the preliminary data, and recently presented at her first scientific meeting. She will work/train with the P.I., and also with 4 expert collaborators, directly in their laboratories for 2 of them. One UM undergraduate student has already worked directly on this project and the investigator will recruit at least two more. Substantial international outreach and collaborative activities are planned across research specialties, especially involving ichthyoplankton colleagues working in different gyre systems, as well as international museum colleagues. This study promises to significantly enhance background knowledge of the vast subtropical gyre surface ecosystem, now heavily impacted, even in mid-ocean, by the incremental accumulation of non-biodegradable, plastic flotsam. This is a major new marine conservation issue that is just now entering public discourse, e.g., see recent descriptions of the North Pacific's Giant Garbage Patch in the popular press.