The Ecology of Cloning

海洋群落中新个体的招募对于确定群落结构至关重要，然而，海洋无脊椎动物生活史的许多基本部分仍然没有得到很好的描述。对海洋无脊椎动物招募的大部分理解是基于以每后代投资为中心的理论，后代在海洋中的扩散，以及后代在发育过程中的生存。海洋无脊椎动物招募的一个主要但在很大程度上被忽视的研究领域是胚胎和/或幼虫阶段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。本计画探讨棘皮动物的克隆生态学，棘皮动物是最广泛报道的分类群。这项工作确定了克隆的环境触发因素，并测试了克隆在生命周期不同阶段的后果。这项工作还通过研究经验，学校演讲和短期课程在缅因州和弗吉尼亚州培训本科生，K-5学生和成人学习者。该项目系统地评估了两个温带沿海栖息地的多个物种克隆的诱导因素和后果。具体来说，这项工作解决了两个主要问题：1）克隆的环境诱导因素是什么？克隆事件在自然界中发生的可能性有多大？2)克隆事件对棘皮动物进入底栖生物群落有什么影响？目前对克隆启动的理解表明，多种应激源可以诱导克隆。然而，潜在的诱导剂很少被系统地研究，也从未在栖息地内或栖息地之间的多个物种中进行过研究。目前的项目做这两个，评估潜在的生物（藻类食物线索和捕食者线索）和非生物（温度，pH值和盐度）参数的变化，以诱导克隆事件在七个物种的温带棘皮动物从两个沿海地区（缅因州和萨利希海海湾）。除了确定克隆的诱导物外，人们对克隆的命运或产生克隆的初级幼虫知之甚少，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）产生的克隆的命运，以确定克隆对青少年招募的潜在贡献。通过跟踪克隆到变态的命运和变态后的几周内，当绝大多数死亡发生时，他们可以估计克隆可能成为海洋无脊椎动物可行的发展途径的程度。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

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.