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

飞行能力是有翼昆虫进化成功的关键。然而，昆虫飞行的起源和它的形态基础还没有被很好地理解。特别是关于翼手目的最后一个共同祖先的飞行器具的形态，目前还没有达成一致意见。此外，从这个祖先进化到蜻蜓、头翅目和新翅目的现存代表以及像古双翅目这样的已灭绝的有翼群体的代表也没有被广泛接受的模式。本项目旨在通过确定飞行器官的同源元素，包括肌肉和硬骨块，阐明昆虫飞行的起源，从而阐明可能的进化路径。为了实现这一点，蜻蜓飞行装置的个体发育将在其三个亚群的几个代表中进行研究，以补充目前支离破碎的知识。结合以前研究的结果和对主要无翼外群体的代表的调查，将确定与飞行有关的肌肉和硬化症的同源性。最后，对翼点飞行器的地形图进行了改造。通过对选定的化石进行重新调查，由此产生的假说将扩展到像古双翅目这样的灭绝物种。这项研究除了使用连续切片和扫描电子显微镜外，还将依靠高分辨率X射线层析成像。结果将决定，关于昆虫飞行起源的相互竞争的假说中，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.