The Ecology of Cloning

招募新的个体进入海洋群落是确定群落结构的关键，然而，海洋无脊椎动物生活史的许多基本部分仍然描述得很少。对海洋无脊椎动物招募的大部分理解都是基于以每一后代的投资、后代在海洋中的传播以及后代在发育过程中的生存为中心的理论。海洋无脊椎动物招募的一个主要的、基本上被忽视的研究领域是在胚胎和/或幼虫阶段进行后代无性繁殖的潜力，也称为克隆。众所周知，克隆发生在不同的海洋类群中，但人们对这种现象的生态后果知之甚少。这个项目研究棘皮动物克隆的生态学，棘皮动物是报道最广泛的分类群。这项工作确定了克隆的环境触发因素，并在生命周期的不同阶段测试了克隆的后果。这项工作还通过研究经验、学校报告和缅因州和弗吉尼亚州的短期课程来培训本科生、K-5学生和成人学习者。该项目系统地评估了来自两个温带沿海生境的多种物种克隆的诱因和后果。具体来说，这项工作解决了两个主要问题：1)克隆的环境诱因是什么？自然界中发生克隆事件的可能性有多大？2)克隆事件对棘皮动物被招募到海底群落的后果是什么？目前对克隆启动的理解表明，多重应激源可以诱导克隆。然而，对潜在诱导者的系统调查很少，而且从未在生境内或跨生境的多个物种中进行过。目前的项目既做了这两项工作，又评估了生物(藻类食物线索和捕食者线索)和非生物参数(温度、pH和盐度)在两个沿海地区(缅因湾和萨利什海)的七种温带棘皮动物中引发克隆事件的可能性。除了确定克隆的诱因外，人们对克隆或产生克隆的初级幼虫的命运知之甚少，因此这种发育现象的生态重要性是一个黑匣子。作为回答第二个问题的一部分，研究人员追踪了在三个不同的生命阶段(合子克隆、早期幼虫克隆和晚期幼虫克隆)产生的克隆到变态及以后的命运，以确定克隆对招募幼虫的潜在贡献。通过跟踪克隆到变态的命运以及在变态之后的几周内，当绝大多数死亡发生时，他们可以估计克隆可能在多大程度上成为海洋无脊椎动物可行的发育途径。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The recruitment of new individuals into marine communities is critical to determine community structure and yet, many basic parts of the life histories of marine invertebrates remain poorly described. Much of the understanding of the recruitment of marine invertebrates is based on theories centered on per-offspring investment, the dispersal of offspring in the ocean, and the survival of offspring during development. A major, largely neglected, area of research of the recruitment of marine invertebrates is the potential for asexual propagation of offspring during the embryonic and/or larval stages, also called cloning. Cloning is widely known to occur in diverse marine taxa, but the ecological consequences of this phenomenon are poorly understood. This project examines the ecology of cloning in Echinoderms, the taxon in which it is most widely reported. The work identifies the environmental triggers of cloning and tests the consequences of cloning at different stages in the life cycle. The work also trains undergraduate students, K-5 students and adult learners through research experiences, school presentations, and short courses in Maine and Virginia. This project systematically evaluates inducers and consequences of cloning in multiple species from two temperate coastal habitats. Specifically, the work addresses two primary questions: 1) What are the environmental inducers of cloning and how likely are cloning events to occur in nature? 2) What are the consequences of cloning events for the recruitment of echinoderms into benthic communities? Current understanding of the initiation of cloning suggests that multiple stressors can induce cloning. Yet potential inducers have only rarely been investigated in a systematic fashion and never across multiple species within habitats or across habitats. The current project does both, assessing the potential for variation in biotic (algal food cues and predator cues) and abiotic (temperature, pH and salinity) parameters to induce cloning events in seven species of temperate echinoderms from two coastal areas (the Gulf of Maine and the Salish Sea). In addition to identifying inducers of cloning, very little is known about the fates of clones or the primary larvae that produce them, and therefore the ecological importance of this developmental phenomenon is a black box. As part of answering this second question, the investigators track the fates of clones that are generated at three different life stages (zygotic clones, early larval clones and late larval clones) to metamorphosis and beyond to determine the potential contribution of cloning to juvenile recruitment. By tracking the fates of clones to metamorphosis and in the weeks immediately following metamorphosis, when the vast majority of mortality occurs, they can estimate the degree to which cloning may be a viable developmental pathway for marine invertebrates.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.