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

飞行的能力对于有翼昆虫的进化成功至关重要。尽管如此，昆虫飞行的起源及其形态学基础仍然没有得到很好的理解。特别是对翼门最后一个共同祖先的飞行器的形态至今没有统一的认识。从这一祖先到蜻蜓目、蜉蝣目和新翅目的现存代表以及到已灭绝的有翅类群如古网翅目的代表的进化也没有被广泛接受的模式。本项目旨在通过鉴定昆虫飞行器官的同源元件，包括肌肉和骨片，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，蜻蜓目飞行类的个体发育将在其三个亚群中的几个代表进行研究，以补充目前零碎的知识。结合以前的研究结果和对主要无翅外群的代表的调查结果，将确定飞行相关肌肉和骨片的同源性。最后，重建了翼类飞行器的地面图案。由此产生的假设将通过重新调查选定的化石扩展到灭绝的群体，如古网翅目。除了使用连续切片和扫描电子显微镜外，调查还将依赖于使用高分辨率X射线断层摄影术。这些结果将使我们能够决定，在关于昆虫飞行起源的各种相互竞争的假说中，哪一种更有可能。

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.