Evolution of Tetrapod Limb Bone Design: Testing the Relationship Between Limb Bone Loads and Locomotion

四足动物肢体骨骼设计的演变：测试肢体骨骼负载与运动之间的关系

• 批准号: 0517340
• 负责人: Richard Blob
• 金额: --
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0517340&HistoricalAwards=false
• 关键词: Evolution; Tetrapod; Limb; Bone; Design

Evolution of Tetrapod Limb Bone Design: Testing the Relationship Between Bone Loads and LocomotionRichard W. BlobClemson UniversityThe limb bones of tetrapods show enormous diversity in shape. It has long been thought that these shape differences were closely related to differences in loads that animal limb bones have to support during locomotion. However, research on the relationship between limb bone loading and limb bone design in animals that use terrestrial locomotion has been dominated by studies of specialized mammals and birds, and the patterns observed in these species might not be true for all vertebrates. For example, some amphibians and reptiles use unconventional types of locomotion, such as jumping in frogs and slow walking in turtles. Studies of how these species deal with the loads placed on their limbs will dramatically expand knowledge of the factors that determine limb bone design. Such studies will provide critical tests of how the loads of locomotion relate to bone shape and the strength of bone material. Such studies will also test whether patterns seen in mammals and birds are evolutionarily primitive features of all vertebrates.This project will address these questions about the form, function and evolution of limb bones by comparing limb bone design with limb bone loads in species from five major groups of vertebrates (frogs, salamanders, turtles, lizards, and basal mammals) that use different forms of terrestrial locomotion (jumping, slow walking, and fast running). Three main types of data will be collected. (1) Forces, stresses, and strains on the femur in nine species (evaluated from surgically implanted strain gauges and force plate data synchronized with high-speed video of limb movements). (2) Mechanical properties (resistance to failure) of the femur in the same species. (3) External and internal measurements of femur shape from a broad range of vertebrate species. These studies will provide the first measurements of limb bone loads in most of these species. The comparative methods used in this project will explicitly analyze limb mechanics data in an evolutionary context. This is a novel approach that will test whether correlations between locomotor style and limb bone loads, shape, and mechanical properties represent new functional adaptations, rather than traits retained from primitive ancestors. These studies will provide tests of long-standing ideas about evolution of bone and locomotion, and will move the field toward comprehensive evolutionary explanations of limb bone properties.This work will enhance training and opportunities for several young scientists, including a postdoctoral researcher, undergraduate and graduate students, and two new faculty members (one from an exclusively undergraduate institution). Results from this work also will be incorporated into instruction for students at two colleges and into materials provided to local science teachers. This project will also provide data for clinical fields (e.g., orthopedics) by examining how the skeleton responds to varying environments and mechanical demands. Finally, by testing hypotheses about correlations between form and function in an evolutionary context, this research will provide a foundation for a broad range of future integrative studies of functional evolution.

四足动物肢体骨设计的演变：骨载荷与运动之间关系的测试。四足动物的肢骨在形状上表现出巨大的多样性。长期以来，人们一直认为这些形状差异与动物四肢骨骼在运动过程中必须支撑的负荷差异密切相关。然而，研究四肢骨负荷和四肢骨设计之间的关系，使用陆地运动的动物一直占主导地位的研究专门的哺乳动物和鸟类，在这些物种中观察到的模式可能不适用于所有脊椎动物。例如，一些两栖动物和爬行动物使用非传统的运动方式，如青蛙的跳跃和乌龟的缓慢行走。研究这些物种如何处理四肢上的负荷，将极大地扩展对决定四肢骨骼设计的因素的认识。 这些研究将提供关键的测试如何运动的负荷与骨骼形状和骨材料的强度。 这项研究亦会测试哺乳动物和鸟类的骨骼模式是否所有脊椎动物在进化上的原始特徴。本计划会比较五个主要脊椎动物组别的四肢骨骼设计和四肢骨骼负荷，以探讨四肢骨骼的形态、功能和进化等问题（青蛙、蝾螈、海龟、蜥蜴和基础哺乳动物）使用不同形式的陆地运动（跳跃、慢走和快跑）。将收集三种主要类型的数据。 (1)9个物种股骨上的力、应力和应变（通过手术植入的应变计和测力板数据与肢体运动的高速视频同步进行评价）。 (2)同一种属股骨的力学性能（抗失效性）。 (3)多种脊椎动物股骨外形的外部和内部测量。 这些研究将提供这些物种中大多数的肢体骨负荷的第一次测量。 在这个项目中使用的比较方法将明确分析肢体力学数据在进化的背景下。 这是一种新的方法，将测试运动风格和肢体骨负荷，形状和机械性能之间的相关性是否代表新的功能适应，而不是从原始祖先保留的特征。 这些研究将为长期存在的关于骨骼和运动进化的观点提供测试，并将推动该领域向肢体骨骼特性的全面进化解释发展。这项工作将加强对几位年轻科学家的培训和机会，包括一位博士后研究员，本科生和研究生，以及两名新教师（其中一名来自一所纯本科院校）。这项工作的结果也将纳入两所大学学生的教学和提供给当地科学教师的材料。 该项目还将为临床领域提供数据（例如，骨科）通过检查骨骼如何响应不同的环境和机械需求。 最后，通过测试进化背景下的形式和功能之间的相关性的假设，这项研究将提供一个广泛的未来功能进化的综合研究的基础。