Evolution of insect flight with emphasis on the ontogenesis of the flight apparatus

飞行能力对有翼昆虫的进化成功至关重要。然而，昆虫飞行的起源及其形态学基础尚不清楚。特别是，对翼龙最后的共同祖先的飞行装置的形态没有一致的看法。此外，从这个祖先进化到现存的齿翅目、蜉蝣目和新翅目的代表动物，再到已灭绝的有翼类群的代表动物，如古翅目，目前还没有一个被广泛接受的模型。本项目旨在通过识别飞行装置的同源元件（包括肌肉和硬骨）来阐明昆虫飞行的起源，从而阐明可能的进化途径。为了实现这一目标，将从其三个亚群的几个代表中研究飞蝇的个体发育，以补充目前零碎的知识。结合先前的研究结果和对主要无翼外群代表的调查，将确定与飞行相关的肌肉和巩膜的同源性。最后，重建翼龙飞行装置的地面模式。由此产生的假设将通过对选定化石的重新调查扩展到已灭绝的类群，如古翅目。除了使用连续切片和扫描电子显微镜外，调查将依靠高分辨率x射线断层扫描。这些结果将使我们能够决定，在关于昆虫飞行起源的相互竞争的假说中，哪一个更有可能。

The ability to fly is essential for the evolutionary success of the winged insects. Neverthe-less, the origin of insect flight and of its morphological foundations is not yet well understood. Especially, there is no agreement on the morphology of the flight apparatus in the last com-mon ancestor of Pterygota. Also for the evolution from this ancestor to the extant representa-tives of Odonata, Ephemeroptera and Neoptera and to the representatives of extinct winged groups like Palaeodictyoptera there is no widely accepted model. The present project aims at clarifying the origin of insect flight by identifying homologous elements of the flight apparatus, including muscles and sclerites, and thus illuminating possi-ble evolutionary pathways. To accomplish this, the ontogenetic development of the flight ap-paratus in Odonata will be studied in several representatives from its three subgroups to supplement the presently fragmentary knowledge. In combination with results from previous studies and from the investigation of representatives from primarily wingless outgroups the homology of flight related muscles and sclerites will be determined. Finally, the ground pat-tern of the flight apparatus of Pterygota will be reconstructed. The resulting hypothesis will be extended to extinct groups like Palaeodictyoptera through reinvestigation of selected fossils. The investigation will rely on using high resolution X-ray tomography besides using serial sectioning and scanning electron microscopy. The results will permit to decide, which of the competing hypotheses on the origin of insect flight is the more probable one.