Aerodynamics, Wing Biomechanics, and the Evolutionary Diversification of the Chiroptera

在这项研究中，PI将调查蝙蝠不同翅膀形式和飞行进化的功能意义。 蝙蝠被选为研究生物体，因为它们包括近1000个物种，体重范围从2到接近2000 g，拥有多种翅膀形状和飞行模式，其特征在于解剖组织（由弹性翼膜互连的刚性骨元素）非常适合建模。 该项目将提出：1）蝙蝠的形态学和翅膀运动学如何影响关节力和力矩以及翅膀内产生的皮肤和骨骼应力？2)蝙蝠的形态学和翅膀的运动学是如何影响翅膀的可操纵性、结构稳定性和空气动力性能以及飞行的机械动力的？3）蝙蝠的飞行是如何从非飞行的哺乳动物进化而来的？这些问题将通过实现一系列相互关联的目标来回答。 以灰头狐蝠为原型，建立了一个飞行蝙蝠的机械和生物学逼真的计算机模型。 然后，该计算机模型用于生成关于在翼关节处产生的力、翼骨和蒙皮中的应力、飞行的机械功率、骨承受屈曲的能力以及翼的稳定性和可操纵性的信息。 该模型将扩展到一组代表不同血统、体型和飞行模式的物种。 这将通过获取有关几个物种的翅膀运动和结构的详细信息，通过捕捉高速视频序列和详细的翼膜应变测量，从这些动物在一个大型风洞中飞行。 将特别注意分析身体大小，飞行模式，机翼形状，飞行速度和生物力学特性对模型输出的影响。 模型的结果将映射到一个良好的支持现存的蝙蝠和他们最近的亲戚，研究飞行性能的演变翼手目。 然后，该模型将被扩展到理论形态提出的蝙蝠祖先，结果将被用来检查的相对优点的假设最早的蝙蝠和蝙蝠飞行的起源的性质。 最后，这种分析结果的复杂性需要新的数据可视化方法。 将开发动态三维图形动画，以大大提高科学家和公众的理解的方式展示结果。 这一三维可视化程序也将在PI网站上实施。 支持文件将用于创建一个网站，以促进高中或一般公众水平的空气动力学，动物飞行和蝙蝠进化的理解。 该网站将部分由本科生，研究生和更高级的工作人员组成的跨学科团队建立，并将利用生物学，工程学和计算机科学。

In this study, the PI will investigate the functional significance of different wing forms and the evolution of flight in bats. Bats have been selected as the study organisms because they comprise close to 1000 species, and range in body mass from 2 to close to 2000 g, possess a diversity of wing shapes and flight modes, and are characterized by an anatomical organization (rigid bony elements interconnected by an elastic wing membrane) that is ideally suited to modeling. This project will ask: 1) how do the morphology and wing kinematics of bats affect the joint forces and moments and the skin and bone stresses developed within the wing?; 2) how do the morphology and wing kinematics of bats affect the maneuverability, structural stability and aerodynamic performance of the wing, and the mechanical power of flight?; and 3) how has bat flight, dictated by these forces and constrained by these results, evolved from non-volant mammals? These questions will be answered by accomplishing a series of interrelated objectives. A mechanically and biologically realistic computer model of a flying bat, based on the grey-headed flying fox, has been developed. This computer model is then used to generate information about the forces developed at the wing joints, the stresses in the wing bones and skin, the mechanical power of flight, the ability of the bones to withstand buckling, and the stability and maneuverability of the wing. The model will be extended to a group of species representing diverse lineages, body sizes and flight modes. This will be accomplished by obtaining detailed information about the wing motions and structure of several species by capturing high speed video sequences and detailed wing membrane strain measurements from these animals flying in a large wind tunnel. Special attention will be paid to the analysis of the effect of body size, flight mode, wing shape, flight speed, and biomechanical properties on the model outputs. Model results will be mapped onto a well-supported phylogeny of extant bats and their closest relatives to examine the evolution of flight performance within the Chiroptera. The model will then be extended to theoretical morphologies proposed for bat ancestors, and results will be used to examine the relative merits of hypotheses about the nature of the earliest bats and the origins of bat flight. Finally, the complexity of the results of this analysis require novel approaches to data visualization. Dynamic three-dimensional graphical animations will be developed to present results in a manner that will greatly increase understanding by both scientists and the general public. This 3-D visualization program will be also be implemented on the PIs web site. Supporting documentation will be used to create a web site to facilitate high school or general public level understanding of aerodynamics, animal flight, and bat evolution. This web site will be built in part by an interdisciplinary team of undergraduates, graduates, and more senior staff, and will draw on biology, engineering, and computer science.