Investigating evolutionary relationships in passerine birds using a total-evidence approach

雀形目（雀形目）由6000多种鸟类组成，占现存鸟类多样性的一半以上。然而，它们的比较形态却没有得到很好的说明和理解，这限制了化石记录在理解这一群体的古代和进化模式方面所能起到的作用，而进化模式导致了现存的生物多样性如此之高。该项目将描述雀形目生物多样性的关键解剖特征，从中获得的见解将用于自信地诊断来自世界各地的假想雀形目化石，并更明确地评估这种非凡的鸟类进化分支的古代和系统发育关系。雀形目是迄今为止最多样化的现存鸟类，但它们的比较形态和化石记录却知之甚少。大规模的雀烷类系统发育研究现在才开始进行（Oliveros等人在回顾中），为描述整个群体的解剖变异提供了一个关键的智力框架，并确定了诊断主要亚支系的共同衍生特征。为了填补这一知识空白，该项目将生成主要雀形目亚支系的三维解剖地图集。单是雀形目就有6000多种，比现存的42种鸟类加起来还要多。这名学生将对雀形目动物标本进行CT扫描，这些标本主要来自剑桥动物博物馆。“数字解剖”技术将应用于野外实验室，使用已经存在的计算资源和软件，以表征整个群体的形态变化，并确定主要雀形目亚支系的解剖突触。这些见解将应用于研究不足的雀形目化石记录，以便为雀形目产生系统发育和地层学审查的最小年龄校准，用于分子分化时间分析。

Passeriformes (passerines) comprise over 6,000 living species of birds-over half of extant avian diversity. However, their comparative morphology is poorly illustrated and understood, limiting the extent to which the fossil record can confidently be brought to bear on understanding the antiquity of the group, and the evolutionary patterns that have resulted in such an extraordinary degree of extant biodiversity. This project will characterise key anatomical features across the living diversity of passerines, insights from which will be used to confidently diagnose putative passerine fossils from around the world and more definitively evaluate the antiquity and phylogenetic relationships of this extraordinary avian clade.Passerines are by far the most diverse extant avian Order, yet their comparative morphology and fossil record are poorly understood. Large-scale phylogenetic studies of passerines are only now being conducted (Oliveros et al. in review), providing a critical intellectual framework for characterising anatomical variation across the group, and identifying shared derived features diagnosing major subclades. To fill this knowledge gap, this project will generate three-dimensional anatomical atlases for major passerine subclades.Alone, passerines comprise over 6,000 species-more than all ~42 other extant avian orders combined. The student will CT scan passerine specimens from across the living diversity of the group, primarily from the Cambridge Museum of Zoology. 'Digital dissection' techniques will be applied in the Field lab using computing resources and software that are already in place in order to characterise morphological variation across the group, and identify anatomical synapomorphies of major passerine subclades. These insights will be applied to the understudied passerine fossil record, in order to generate phylogenetically and stratigraphically vetted minimum age calibrations for passerines to be applied in molecular divergence time analyses.