Comparative Mechanics of Rapid Predatory Movements

即使是最强大的肌肉也收缩得太慢，距离太短，无法达到我们在许多快速掠夺性动物运动中看到的令人难以置信的速度和加速。人类通过十字弓等工程系统绕过了这些限制，在这种系统中，缓慢的手臂运动通过弓的弹性能量存储转化为快速的箭运动，并通过闩锁快速释放能量。在进化史上，动物通过类似于弓和箭的力量放大机制反复克服了肌肉收缩的极限，但科学家们缺乏对这些系统中的进化变异和力量扩大的潜在物理原理之间的相互作用的广泛理解。这个研究项目的重点是螳螂虾(口足目)，它是动物界中产生最快、最有力的捕食运动之一。猛烈攻击发生在几毫秒内，速度可以达到超过20米/S；一些物种可以以超过1000牛顿(其体重的数千倍)的冲击力进行攻击。这些令人印象深刻的动作是由缓慢收缩的肌肉控制的，这些肌肉激活了包括弹簧、闩锁、连杆和杠杆臂在内的权力放大结构网络。这种能量放大系统在450种口足类动物中是保守的，但它们的食肉附属物非常多样化，从带刺的和带刺的长矛到斧头和锤子。为了解决生物功率放大的广泛进化模式和基本物理原理，该项目综合了三种方法：(1)跨物种形态和性能的生理和运动学分析；(2)应用一个模型，该模型综合和解释了弹簧、连杆和杠杆臂在功率放大和性能中的相对作用；以及(3)将模型变量的动态与它们在物种间观察到的实际变化进行比较分析。通过整合生理学、物理学和进化模式，这项研究的结果将提供对生物功率放大系统的基本见解。这一建议的更广泛影响包括，它是综合性的，结合了生物学和工程学原理，并侧重于培训和教育不同的学生群体，包括妇女和代表性不足的少数群体。这项研究的结果将通过NSF资助的项目(例如，了解进化)和与科学媒体的合作向公众提供。

Even the most powerful muscles contract too slowly and over distances too short to achieve the incredible speeds and accelerations that we see in the many rapid predatory movements of animals. Humans circumvent these limitations with engineered systems like the crossbow, in which slow arm movement is transformed into rapid arrow movement through the elastic energy storage of the bow and rapid energy release via a latch. Repeatedly over evolutionary history, animals have overcome the limits of muscle contractions through power amplification mechanisms similar to that of the bow and arrow, and yet scientists lack a broad understanding of the interplay between the evolutionary variation in these systems and the underlying physical principles of power amplification. This research project focuses on mantis shrimp (Stomatopoda), which generate among the fastest and most forceful predatory movements in the animal kingdom. Raptorial strikes occur within several milliseconds and can reach speeds of over 20 m/s; some species can strike with impact forces of over 1000 N (thousands of times their body weight). These impressive movements are controlled by slowly contracting muscles that activate a network of power amplification structures including springs, latches, linkages and lever arms. This power amplification system is conserved across the 450 species of stomatopods, yet their raptorial appendages are remarkably diverse, ranging from spiny and barbed spears to hatchets and hammers. To address the broad evolutionary patterns and the fundamental physical principles of biological power amplification, this project integrates three approaches: (1) physiological and kinematic analyses of morphology and performance across species; (2) application of a model that integrates and accounts for the relative roles of springs, linkages and lever arms in power amplification and performance; and (3) comparative analyses of the dynamics of the model variables compared to their actual variation observed across species. Through the integration of physiology, physics and evolutionary patterns, the results of this research will provide fundamental insights into biological power-amplified systems, in general. The broader impacts of this proposal include that it is integrative, combines biology and engineering principles, and focuses on the training and education of a diverse group of students including women and underrepresented minorities. The findings from this research will be provided to the public through NSF-funded programs (e.g., Understanding Evolution) and collaborations with the scientific press.