Modeling how keystone individuals emerge and influence disease transmission

集体行为源于组成复杂系统的代理人的协调行动。人类生活 在复杂的社会中，如国家和民族，组织中的细胞集体协调它们的行动， 发展，动物群体进行集体行为，如群集。因此，了解如何 集体行为的出现对广泛的学科有着根本性的影响。传统研究 集体行为将群体中的所有个体视为相同的行为者。然而，个体差异是 在自然界和集体中普遍存在的基因几乎总是由表型异质的个体组成。 这种异质性导致了某些个体的不成比例的巨大影响，这些个体在这里被称为 “关键个人”，而不是群体的集体表现。这样的关键人物在 例如，生物学中的“超级传播者”促进了流行病在人类社会中的快速传播，“先驱”细胞 在发育过程中协调其他细胞的运动，某些个体监督其他细胞的行为 在人类和非人类灵长类动物群体中。因此，令人惊讶的是，只有很少的理论或 解释关键个体对集体行为的原因和后果的实证研究。我们的目标 是揭示关键个体在塑造集体结果中的作用，特别是疾病动态， 通过研究社会蜘蛛，Stegodyphus dumicola，这是非常适合实验操作。 我们将开始揭示如何基石个人导致之间的权衡有益的集体成果 和疾病传播。我们将结合联合收割机经验的工作与代理为基础的模拟和常微分 对集体成果进行成本效益分析。这一分析将揭示如何影响 当同时考虑到多个集体成果时，集体成功的基石就会改变。我们 将决定关键个体影响其他群体的遗传和社会机制 成员在许多学习系统中，包括我们的学习系统，关键个体在其学习过程中催化行为变化。 集团成员。利用基因表达分析和社会网络理论，我们将揭示 个体通过社会互动和对基因表达的影响引起行为变化。特别是， 我们将重点关注由关键个体引起的基因表达的变化， 正常的免疫功能我们的最后一个目标是剖析疾病动力学是如何介导的基石个人。 基于模型预测，我们将研究病原体传播动力学是否受到以下两个因素的影响： 第一个被感染的个体（零号病人）和决定菌落组成的行为规则。我们将测试 这是通过追踪标记的细菌在整个殖民地中的传播来实现的， 第一个感染者。通过研究机制和功能，使用实验和 模型，我们的工作将填补经验和理论空白，我们的理解如何基石个人 影响集中于疾病在社会中传播的集体结果。

Collective behavior emerges from the coordinated actions of agents comprising complex systems. Humans live in intricate societies such as states and countries, cells in a tissue collectively coordinate their actions during development, and animal groups perform collective behaviors such as flocking. Thus, understanding how collective behaviors emerge has fundamental implications for a wide range of disciplines. Traditional studies of collective behavior have treated all individuals in a group as identical agents. However, individual variation is prevalent in nature and collectives are almost always comprised of phenotypically heterogeneous individuals. This heterogeneity results in a disproportionately large influence of certain individuals referred to here as ‘keystone individuals’, over the collective performance of the group. Such keystone individuals are prevalent in biology, for example, ‘super-spreaders’ facilitate the rapid spread of epidemics in human societies, ‘pioneer’ cells coordinate the movement of other cells during development, and certain individuals police the behavior of others in human and non-human primate groups. Therefore, it is surprising that there has been only little theoretical or empirical work explaining the causes and consequences of keystone individuals on collective behavior. Our goal is to uncover the role of keystone individuals in shaping collective outcomes, and in particular disease dynamics, by studying the social spider, Stegodyphus dumicola, which is highly amenable to experimental manipulations. We will begin by uncovering how keystone individuals lead to tradeoffs between beneficial collective outcomes and disease transmission. We will combine empirical work with agent-based simulations and ordinary differential equations to produce a cost-benefit analysis of collective outcomes. This analysis will reveal how the effect of keystones on collective success changes when multiple collective outcomes are considered simultaneously. We will then determine the genetic and social mechanisms by which keystone individuals influence other group members. In many study systems, including ours, the keystone individual catalyzes behavioral changes in its fellow group members. Using gene expression analysis and social network theory we will uncover how keystone individuals cause behavioral changes through social interactions and influence on gene expression. In particular, we will focus on the changes caused by keystone individuals to the expression of genes that are responsible for proper immune function. Our last aim is to dissect how disease dynamics are mediated by keystone individuals. Based on model predictions, we will examine if pathogen spread dynamics are influenced by both the identity of the first infected individual (patient zero) and the behavioral rules that determine colony composition. We will test this by tracing the spread of tagged bacteria throughout the colony when a keystone or generic individual are the first infected individual. By investigating mechanisms and function using a combination of experiments and modeling, our work will fill empirical and theoretical gaps in our understanding of how keystone individuals influence collective outcomes focusing on disease spread through a society.