PEET: Lower Worms Of The Meiofauna - Models for Early Metazoan Evolution

在生活在海洋环境中沙粒之间的小型无脊椎动物中，有一种微小的、神秘的蠕虫，许多人认为它是所有双边对称动物中最原始的(也就是说，除了海绵动物和海绵动物以外的所有动物)。这些蠕虫包括两个小类，分别称为扁形蠕虫和链状涡虫，它们现在被归入扁形蠕虫门，但根据一些系统学家的说法，它们甚至可能与更常见的扁形蠕虫无关，如扁形动物和多壳类。另一个原始蠕虫类群是口甲虫，它与其他无脊椎动物门的关系也同样存在争议；根据某些理论，口甲虫就像扁虫的祖先。S.Tyler和W.Sterrer长期研究这些蠕虫，他们建议培训新学生如何发现和处理它们，以及如何破译系统关系。在缅因州大学S.Tyler实验室工作的学生将专注于扁虫类群的显微技术和分类学。通过对这些动物应用荧光和电子显微镜观察到的新特征表明，现有的分类系统不能很好地反映它们之间的关系。学生们与斯特雷尔在百慕大的实验室一起工作，并陪同他进行采样旅行，他们将测量扁虫和颌口虫的分布模式，并收集标本进行显微镜和分子研究。他还将培训学生的策展技术。这个项目的主要重点是培训学生-给他们工具来发现和描述这些难以找到但非常丰富的许多物种，并理解它们的多样性。如果没有新的研究人员接受培训来识别这些神秘的动物，我们将失去解决动物起源重要问题所需的专业知识。这些学生发现的知识可能会为解决主要动物群体如何相关的深远问题提供关键线索。识别和确定许多未描述的低等扁虫物种的特征将有助于更好地了解它们的生物多样性；了解这些扁虫和节口蠕虫的地理分布应该为了解它们在哪里出现以及它们如何多样化并在地球上传播提供了一种手段。这些学生的研究结果将显示在一个网站上，这样任何有网络浏览器的人都可以使用这些数据来识别他们可能发现的类似蠕虫，或者评估地理站点的历史关系。

AbstractAmong the small invertebrates living between sand grains in the marine environment, are tiny, cryptic worms that many consider to be the most primitive of all bilaterally symmetrical animals (that is, all animals excluding the cnidarians and sponges). These worms include two small groups called acoel and catenulid turbellarians which are now classified in the phylumPlatyhelminthes (flatworms) but that, according to some systematists, may not even be related to the more familiar flatworms such as planarians and polyclads. Another of these primitive worm groups is the Gnathostomulida, whose relationships to other phyla of invertebrates have been similarly controversial; by some theories, gnathostomulids are like the ancestors of the flatworms. S. Tyler and W. Sterrer, who have long studied these worms, propose training new students in how to find and handle them and in how to decipher systematic relationships. Students working in S. Tyler's laboratory at the University of Maine will concentrate on microscopical techniques and taxonomy of flatworm groups. New characters discerned through applying fluorescence and electron microscopy on these animals show that the relationships among them are not well represented by the current classification system. Students working with Sterrer in his laboratory in Bermuda and accompanying him on sampling trips will gauge patterns of distribution of flatworms and gnathostomulids and gather specimens for the microscopical and molecular studies. He will also train students in curatorial techniques.The major focus of this project is the training of students-to give them the tools to discover and describe the many species of these difficult-to-find, yet remarkably abundant, enigmatic animals and to make sense of their diversity. Without new researchers being trained to identify these cryptic animals, we will lose the expertise needed to address important questions of animal origins. The knowledge these students unearth will likely provide critical clues to resolve far-reaching questions of how the major groups of animals are related. Identifying and characterizing the many undescribed species of lower flatworms will provide a better understanding of their biodiversity; knowledge of the geographic distribution of both these flatworms and gnathostomulids should provide a means for seeing where they arose and how they diversified and spread around the Earth. The results of these students' research will be displayed on a Web site so that anyone with a Web browser can use that data to identify similar worms they might find or to gauge the historical relationships of geographic sites.