Collaborative Research: RUI: The challenges of living small: functional tradeoffs in the vertebral bone structure of diminutive mammals

合作研究：RUI：小型生活的挑战：小型哺乳动物椎骨结构的功能权衡

• 批准号: 2223965
• 负责人: Charles Stayton
• 金额: $ 19.83万
• 依托单位: Bucknell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2223965&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; challenges; living

This research explores how body size affects the structure and function of bones in very small (miniaturized) mammals. Miniaturization is common across animal groups and is significant because it is often associated with the evolution of new features despite the unique challenges faced by small animals. The effects of miniaturization on the vertebrate skeleton are particularly fundamental because the skeletal system supports all other organ systems, and must withstand internal and external applied forces while still facilitating efficient body motion. It remains poorly understood how the skeletons of the smallest vertebrate animals withstand and transmit everyday forces. 3D imaging techniques, computer modeling, and physical testing on mammalian backbones (vertebrae) will be used to assess how the skeletons of several related groups of small mammals (shrews, moles, hedgehogs, and solenodons) have evolved to function at small size. The project is testing whether smaller bones are stronger (more resistant to breaking) or stiffer (more resistant to bending), and how internal and external bone structure work together to allow very small mammals to move safely and efficiently. Planned activities will promote scientific and public understanding of how natural selection leads to changes in the shapes of bones, and how body size influences the way animals interact with their environment. This project involves training of six students from a primarily undergraduate institution (Bucknell University) in independent research. Outreach activities through the Field Museum will promote public awareness of the incredible diversity and importance of small mammals, which are often overlooked but are critical to ecosystem function.This research leverages the taxonomic richness and ecological and body size diversity of the mammalian clade Eulipotyphla to: 1) measure the contributions of trabecular and cortical bone tissues to whole-bone performance in the eulipotyphlan lumbar spine; 2) quantify the selective pressures to maximize bone strength, stiffness, or both in very small mammals; and 3) determine when tradeoffs between strength and stiffness occur as very small mammals adopt novel ecologies. By focusing on the morphology and performance of trabecular and cortical bone in the axial skeleton, specifically the lumbar spine, this research takes advantage of a system that is developmentally constrained via Hox patterning but also morphologically plastic and heavily involved in quadrupedal locomotion. The integrative approach of this study synthesizes Finite Element Analysis (FEA) results with body size, phylogenetic, ecological, and morphometric data to assess morpho-functional tradeoffs and quantify selective pressures on vertebral bone. The use of Eulipotyphla for this clade-wide functional study is novel but appropriate, as the group is taxonomically and ecologically diverse and includes the smallest mammal by mass (weighing less than two grams). These investigations will yield novel quantitative evidence about the relative importance of, and interaction between, trabecular and cortical bone under stress, and test long-standing hypotheses about how selection acts on bone morphology to produce appropriately strong, stiff bony structures at small sizes. In addition, educational and outreach outcomes include undergraduate research training, a treasure hunt activity to find small mammals at the Field Museum, and a learning kit for the Field Museum to support middle school learning standards.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.

这项研究探讨了体型如何影响很小（微型）哺乳动物中骨骼的结构和功能。小型群体中的小型化是很普遍的，并且很重要，因为尽管小动物面临着独特的挑战，但它通常与新特征的演变有关。小型化对脊椎动物骨骼的影响特别基本，因为骨骼系统支持所有其他器官系统，并且必须承受内部和外部施加力，同时仍促进有效的身体运动。它仍然不太了解最小的脊椎动物动物的骨骼如何承受和传播日常力量。 3D成像技术，计算机建模和哺乳动物骨架上的物理测试（椎骨）将用于评估几个相关小型哺乳动物（shrews，moles，刺猬和螺旋桨）的骨骼如何演变为在小尺寸中发挥作用。该项目正在测试较小的骨骼是否更强（对破裂更具抗性）或更硬（对弯曲更具抗性），以及内部和外部骨骼结构如何共同起作用以使非常小的哺乳动物可以安全有效地移动。计划的活动将促进科学和公众对自然选择如何导致骨骼形状变化的理解，以及身体大小如何影响动物与环境的互动方式。该项目涉及培训主要研究生学院（巴克内尔大学）的六名学生。通过田野博物馆通过宣传活动将提高公众对小型哺乳动物的难以置信的多样性和重要性的认识，这些哺乳动物通常被忽视，但对生态系统的功能至关重要。这项研究利用了哺乳动物进化枝的分类丰富性，生态和身体大小的多样性。腰椎； 2）量化选择性压力，以最大化骨骼强度，刚度或两者兼有很小的哺乳动物； 3）确定力量和刚度之间的权衡何时发生，因为很小的哺乳动物采用新颖的生态。通过专注于小梁和皮质骨在轴向骨骼（特别是腰椎）中的形态和性能，该研究利用了一种通过HOX图案开发的系统，但在形态上塑性却有塑性，并且在四足体系上也参​​与了大量塑性。这项研究的综合方法综合了有限元分析（FEA）的结果，并与体型，系统发育，生态和形态计量数据合成，以评估形态功能的权衡取舍并量化椎骨上的选择性压力。在整个进化枝范围的功能研究中，使用Eulipotyphla是新颖但合适的，因为该组在分类学和生态学上是多样的，并且包括质量最小的哺乳动物（重量少于两克）。这些研究将产生有关小梁和皮质骨在压力下的相对重要性以及相互作用的相对重要性的新颖定量证据，并检验了关于选择如何在骨形态上作用以在小尺寸上产生适当强，僵硬的骨质结构的长期假设。此外，教育和外展成果包括本科研究培训，寻宝活动，在野外博物馆找到小型哺乳动物，以及野外博物馆的学习套件，以支持中学学习标准。该奖项反映了NSF的法定任务，并通过评估该基金会的知识分子功能和广泛的影响来审查Criteria。