CAREER: The evolutionary causes and functional consequences of sexual dimorphism in flight muscle size in birds

该项目旨在了解为什么许多（但不是全部）鸟类的雄性和雌性在飞行肌肉的大小上存在差异，以及这些差异如何影响它们的飞行。鸟类的飞行一直是并将继续是工程师设计更好的飞行器的灵感来源，但鸟类解剖学上的微小差异，比如同一物种内部的差异，如何影响飞行能力，仍有很多未知之处。这个项目也有很强的教育成分：本科生将参与研究的各个方面，学习创建假设，设计研究，收集和分析数据，并撰写结果。本科生物学课程的学生将创建以游戏为基础的脊椎动物解剖学教材，用于当地儿童科学中心和学前教育教室。在这样做的过程中，他们将获得宝贵的科学传播技能，同时提高他们对解剖学的理解。来自农村社区服务不足的儿童将受益于为他们设计的新的引人入胜的教育材料。该项目的目的是了解为什么许多鸟类在飞行肌肉大小上表现出性别二态性，而许多其他鸟类却没有，并了解这种飞行肌肉大小的二态性如何影响野生鸟类的飞行性能。一个由本科生、一名博士后和首席研究员组成的团队将编制一个数据集，其中包括至少1000个物种的至少5个雄性和5个雌性标本的骨骼测量数据，以及物种生活史和生态特征的补充数据集，以测试关于哪种生态特征最能预测飞行肌肉大小的性别二态性的假设。为了了解飞行肌肉大小的两性二态性是如何影响飞行性能的，高速摄像机将用于测量鸟类在多种条件下进行逃跑式起飞的速度和加速度：自然、垂直、穿越障碍，以及在每种情况下负重。这些实验将在三种不同的物种中进行：一种是雄性比雌性有更大的飞行肌肉，一种是雌性有更大的飞行肌肉，还有一种在飞行肌肉大小上没有表现出性别二态性。该项目将大大增加我们对种内变异的程度和后果的理解，为工程师提供有关小型飞行器设计的见解，并为学生提供定量研究的机会，为他们从事STEM职业做好准备。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project aims to understand why males and females of many (but not all) types of birds differ in the size of their flight muscles, and how these differences affect their flight. Flight in birds has been and continues to be an inspiration for engineers designing better flying machines, but much is still unknown about how small differences in bird anatomy, like those within a species, influence flight ability. This project also has a strong educational component: undergraduate students will be involved in all aspects of the research, learning to create hypotheses, design studies, collect and analyze data, and write up results. Students in an undergraduate biology course will create play-based vertebrate anatomy teaching materials for use in a local children’s science center and in Head Start preschool classrooms. In doing so, they will gain valuable skills in science communication while improving their understanding of anatomy. Underserved children from a rural community will benefit from new engaging educational materials designed for them. The aims of this project are to understand why many species of birds exhibit sexual dimorphism in flight muscle size, but many others do not, and to understand how this dimorphism in flight muscle size impacts flight performance in wild birds. A team of undergraduate students, a postdoc, and the principal investigator will compile a dataset of skeletal measurements of at least five male and five female specimens each for at least 1,000 species, with a complementary dataset on species life history and ecological traits, to test hypotheses about which ecological traits best predict sexual dimorphism in flight muscle size. To understand how sexual dimorphism in flight muscle size affects flight performance, high-speed video cameras will be used to measure velocity and acceleration of birds engaging in escape-style takeoffs under multiple conditions: natural, vertical, through an obstacle course, and in each of these settings while carrying additional weight. These experiments will be conducted in three different species: one in which males have larger flight muscles than females, one in which females have larger flight muscles, and one that does not exhibit sexual dimorphism in flight muscle size. The project will greatly increase our understanding of the extent and consequences of intraspecific variation, offer insights to engineers regarding the design of small aerial vehicles, and provide opportunities for students in quantitative research to prepare them for STEM careers.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.