Use of CR1 Insertions to Dissect a Deep Polytomy in Anseriformes

反刍动物（尖叫动物、鸭子、鹅和天鹅）之间的系统关系几十年来一直存在争议。人们试图通过形态学、行为学和分子方法来解决这些关系，但这棵树的重要部分仍未得到解决。这项研究使用了一种新的方法，试图通过分离和表征基因组中某些物种存在转座因子（称为CR1）而其他物种不存在的特定位点，来解决该树中的主要多聚现象。这些方法最近在哺乳动物系统发育的研究中被证明是强有力的，人们希望它们在鸟类的研究中也同样重要。该项目更广泛的影响包括向许多本科生介绍基因组研究，包括代表性不足的群体，并向其他访问以保护遗传学和系统学为重点的大学中心的科学家介绍一般概念。鸟类中CR1的研究也将增加对基因组中转座因子活性的科学理解。这些元素占人类基因组的一半以上，并且由于各种原因越来越多地被认为是真核生物基因组的重要组成部分。最后，这项研究的核心技术在系统学领域之外还有许多其他应用，并将允许从许多与鸟类无关的生物体的未表征基因组中分离出各种各样的DNA目标。

Systematic relationships among Anseriformes (screamers, ducks, geese and swans) have remained controversial for decades. Major attempts to resolve these relationships have been made using morphological, behavioral and molecular approaches, yet important parts of the tree remain unresolved. This study uses a new approach in an attempt to resolve a major polytomy within that tree by isolating and characterizing specific sites in the genome where a transposable element (called CR1) is present in some species, but not in others. Such approaches have recently proven powerful for studies of mammalian phylogeny, and it is hoped that they will be similarly important in studies of birds.The project's broader impacts include the introduction of genomic studies to many undergraduate students including underrepresented groups and the introduction of the general concepts to other scientists visiting a university-based center focused on conservation genetics and systematics. Studies of CR1 in birds will also increase scientific understanding of the activity of transposable elements within genomes. Such elements comprise over half of the human genome, and are increasingly recognized as being important components of eukaryotic genomes for an increasing variety of reasons. Finally, the technique that is central to this study has many other applications beyond the field of systematics and will allow the isolation of a wide variety of DNA targets from uncharacterized genomes of many organisms unrelated to birds.