Molecular Phylogenetics and a Time Scale for Diversification of the Higher Flies (Diptera: Eremoneura)

brian M. wiegmann博士；北卡罗来纳州立大学的布莱恩·维格曼和杰弗里·l·索恩获得了一项研究经费，用于研究一种具有重要经济意义的昆虫类群的系统发育关系。有近6万种已被描述的昆虫，即高蝇类（昆虫纲：双翅目：短翅目），是中生代时期最大、最成功的昆虫辐射之一。相互矛盾的形态学解释已经引发了一场争论的关系，主要亚群在埃蒙纳亚。关于两种主要的神经动物类群的基础谱系，empido总科和环缝总科，一直有特别的争议。尽管最近引起了人们的关注，但尚未有分子研究解决神经细胞的分类问题。该合作项目将综合形态学和分子证据来重建基础神经动物进化的时间和模式。最近提出的从核苷酸序列数据估计分化时间的方法不需要生物学上难以置信的假设，即分子进化速率随时间不变。这种估计散度时间的方法很有前途，但尚未得到充分的评价或改进。在这个项目中阐明的Eremoneuran关系，以及最近的化石证据汇编，将作为新方法估计分化时间能力的测试系统。将进行以下分析：1)检验已发表的关于双翅目基本家族群关系的假设，2)检验蝶科的单系性及其作为环折纲的姐妹类群的地位，3)重建双翅目分化时间，并检验分化时间估计方法对不同基因和树拓扑结构的稳健性。双翅目是遗传、发育、遗传和遗传的模型系统，因此重建双翅目双翅目的分子系统发育和重建时间尺度将非常有价值。以及进化生物学。整合短尾虫系统发育的分子和形态学证据将最终为揭示与中生代主要昆虫辐射相关的模式和原因提供一个框架。

DEB-0089745Brian M. WiegmannDrs. Brian Wiegmann and Jeffrey L. Thorne of North Carolina State University have been awarded a grant to study phylogenetic relationships of an economically important instect group. With nearly 60,000 described species, the Eremoneura, or higher-flies (Insecta: Diptera: Brachycera), are among the largest and most successful of Mesozoic-aged insect radiations. Conflicting morphological interpretations have fueled a debate over the relationships of the major subgroups within Eremoneura. The basal lineages of the two major eremoneuran groups, Empidoidea and Cyclorrhapha, have been particularly controversial. Despite recent attention, no molecular studies have yet addressed eremoneuran classification. This collaborative project will synthesize morphological and molecular evidence to reconstruct the timing and pattern of basal eremoneuran evolution. Recently proposed methods for estimating divergence times from nucleotide sequence data do not require the biologically implausible assumption that rates of molecular evolution are constant over time. Such methods for estimating divergence times are promising but have not yet received adequate evaluation or refinement. Eremoneuran relationships that are elucidated within this project, and recent compilations of fossil evidence will serve as a test system for the ability of new methods to estimate divergence times. Analyses will be carried out to: 1) test published hypotheses for the basal family-group relationships of Eremoneura, 2) test the monophyly of the Empidoidea and its position as proposed sister-group to the Cyclorrhapha, 3) reconstruct eremoneuran divergence times and test the robustness of divergence time estimation methods to differing genes and tree topologies, Molecular phylogenies and a reconstructed time scale for eremoneuran Diptera will be extremely valuable because Diptera are model systems for genetic, developmental, and evolutionary biology. Integration of molecular and morphological evidence on brachyceran phylogeny will ultimately provide a framework for uncovering patterns and causes associated with major Mesozoic-aged insect radiations.