Collective Ecophysiology and Physics of Social Insects

社会昆虫的集体生态生理学和物理学

• 批准号: 1606895
• 负责人: Lakshminarayana Mahadevan
• 金额: $ 47.43万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1606895&HistoricalAwards=false
• 关键词: Collective; Ecophysiology; Physics; Social; Insects

Insects are the most diverse species on our planet, numbering more than five million different types, and have exploited nearly every terrestrial and many aquatic and aerial niches. Social insects, those that form cooperative societies with specialized castes based on division of labor, for example, afford spectacular examples of collective behavior in such instances as termite mounds, locust swarms and bee clusters and hives. These collective architectures are functional and allow the organisms to maintain a relatively uniform micro-environment even with a variable macro-environment. Understanding how this is achieved in a variety of climates and environments is not just a problem in ecology or physiology, but also one in physics, given that they exchange information, energy and matter continually with the environment. The study looks at the collective dynamics of bee colonies that maintain their temperature in a closed environment using active ventilation driven by fanning, and the structural dynamics of actively adherent bee clusters that can respond to vibrotactile stimuli by changing their shape. While current studies in active matter primarily focus on the patterns in space and time that result from interactions, the new experimental and theoretical approaches will focus on how active systems can perform functions by coupling form, flows and forces in the presence of feedback. Organisms live in varying environments and must therefore be able to tolerate variations in the macro-environment they inhabit. They do this by creating niches that damp out the large scale variations without completely isolating themselves. Outside human societies, nowhere is this better seen than in social insects. The current study takes a quantitative physical approach to the problem, building on the empirical information obtained by biologists. It aims to partially break down the artificial barrier between physics and biology, i.e. between non-living and living matter by showing how living matter shapes itself and its physical non-living environment to achieve function. By synthesizing aspects of hydrodynamics, statistical mechanics and decision making for active matter systems, the research will thus have impact on a range of biological and engineered systems where behavior and decision making come together with flows and forces.The collective behavior of the organisms creates environmental micro-niches that buffer them from environmental fluctuations e.g. temperature, humidity, mechanical perturbations etc., thus coupling organismal physiology, environmental physics and population ecology. The current study proposes to use a combination of biological experiments, theory, computation and robotic biomimicry to understand how a collective of bees can integrate physical and behavioral cues to attain a non-equilibrium steady state that allows them to resist and respond to environmental fluctuations of forces and flows. The researchers will analyze how bee clusters change their shape and connectivity and gain stability by spread-eagling themselves in response to mechanical perturbations, using a combination of optical and x-ray imaging techniques. Similarly, the researchers will study how bees in a colony respond to environmental thermal perturbations by deploying a fanning strategy at the entrance that they use to create a forced ventilation stream that allows the bees to collectively maintain a constant hive temperature. When combined with quantitative analysis and computations in both systems, the researchers will integrate the sensing of the environmental cues (acceleration, temperature, flow) and convert them to behavioral outputs that allow the swarms to achieve a dynamic homeostasis, that will be tested using collective robotics using simple agents that can sense each other, their environment and move in response to both cues.

昆虫是我们这个星球上最多样化的物种，有500多万种不同的种类，它们几乎利用了每一个陆地生态位、许多水生生态位和空中生态位。例如，群居昆虫，即那些在劳动分工的基础上形成具有特殊等级的合作社会的昆虫，提供了集体行为的壮观例子，如白蚁丘、蝗虫群、蜂群和蜂巢。这些集体结构是功能性的，允许生物体在宏观环境变化的情况下保持相对统一的微环境。了解在各种气候和环境中如何实现这一目标不仅是生态学或生理学的问题，也是物理学的问题，因为它们不断地与环境交换信息、能量和物质。该研究着眼于蜂群的集体动力学，蜂群在一个封闭的环境中使用扇形驱动的主动通风来保持温度，以及积极粘附的蜂群的结构动力学，这些蜂群可以通过改变形状来响应振动触觉刺激。虽然目前对活性物质的研究主要集中在空间和时间上的相互作用模式，但新的实验和理论方法将集中在活性系统如何在反馈存在的情况下通过耦合形式、流动和力来执行功能。生物体生活在不同的环境中，因此必须能够忍受它们所居住的宏观环境的变化。它们通过创造小生境来做到这一点，这些小生境在不完全孤立自己的情况下抑制了大规模的变化。在人类社会之外，这一点在群居昆虫身上表现得最为明显。目前的研究以生物学家获得的经验信息为基础，采用定量的物理方法来解决这个问题。它旨在通过展示生物如何塑造自身及其物理非生物环境来实现功能，从而部分打破物理与生物学之间的人为屏障，即非生命物质与生命物质之间的屏障。通过综合流体力学、统计力学和活性物质系统决策的各个方面，这项研究将对一系列生物和工程系统产生影响，在这些系统中，行为和决策与流动和力结合在一起。生物的集体行为创造了环境微生态位，缓冲它们免受环境波动（如温度、湿度、机械扰动等）的影响，从而将生物生理学、环境物理学和种群生态学结合起来。目前的研究建议使用生物实验、理论、计算和机器人仿生学相结合的方法来理解一群蜜蜂如何整合物理和行为线索，以达到一种非平衡的稳定状态，使它们能够抵抗和响应环境的力和流量波动。研究人员将利用光学和x射线成像技术的结合，分析蜂群如何改变它们的形状和连通性，并通过对机械扰动的反应，通过展开鹰状自身来获得稳定性。同样，研究人员将研究蜂群中的蜜蜂是如何对环境热扰动做出反应的，方法是在入口部署扇风策略，它们利用扇风策略创造一个强制通风流，使蜜蜂能够集体保持恒定的蜂巢温度。当与两个系统中的定量分析和计算相结合时，研究人员将整合对环境线索（加速度，温度，流量）的感知，并将其转换为行为输出，使蜂群实现动态稳态，这将使用集体机器人进行测试，使用简单的代理，可以感知彼此，它们的环境并根据两种线索移动。