Relationships and Classification of Primitive Hexapods and Insects

该项目将利用分子序列和形态数据相结合的方法，研究四个基本六足类群--Entognatha、Thysanura、Paleoptera和Plecoptera的系统发育关系。在这四个谱系的起源中，我们发现了自泥盆纪以来定义昆虫多样性的基本事件。阐明这些群体之间的关系将允许更准确地解释它们的属性。此外，现存分类群的强大分支图将有助于我们对有问题的化石分类群的理解。将确定核18S rDNA区域的DNA序列。这些数据将直接与形态特征矩阵相结合。将根据较低等级级别的系统关系为每个较高的类群选择具有代表性的类群。利用早期研究的结论，将选择分支较远的类群来推断六足纲、昆虫纲、双翅目和新翅目的地面平面图。酒精保存和干燥的博物馆标本将被用来确保尽可能纳入最基本的谱系，从而产生更可靠的数据集。这种方法结合了多个基因座、基于系统发育的采样和广泛的形态分析，确保了这项工作将增加我们对这些最古老的六足动物谱系的进化和系统学的理解。

This project will examine the phylogenetic relationships of four basal hexapod groups--Entognatha, Thysanura, Paleoptera and Plecoptera--using a combination of molecular sequence and morphological data. In the origin of these four lineages, we find the fundamental events that define insect diversity since the Devonian. Illuminating the relationships among these groups will allow a more precise interpretation of their attributes. Moreover, robust cladograms of extant taxa will aid in our understanding of problematic fossil taxa. DNA sequences will be determined for the nuclear 18S rDNA regions. These data will be combined directly with a matrix of morphological features. Representative taxa will be chosen for each of the higher groups based on the systematic relationships at lower hierarchical levels. Using the conclusions of earlier studies, cladistically distant taxa will be chosen to infer the ground plans of Hexapoda, Insecta, Dicondylia, and Neoptera. Alcohol-preserved and dried museum specimens will be used to assure the inclusion of the most basal lineages possible, thereby yielding a more robust data set. This approach, combining multiple loci, phylogenetically based sampling and extensive morphological analysis, ensures that this work will increase our understanding of the evolution and systematics of these, the oldest hexapod lineages.