Collaborative Research: Integrative Approach to Understanding the Emergence of Alternate Social Phenotypes through Greenbeard Effects in the Fire Ant

合作一直是一个长期存在的进化问题，因为合作者遭受个体适应性损失，以向群体中的其他个体提供利益。这个问题的一个著名的解决方案涉及绿胡子效应，首先由W.D.汉密尔顿在20世纪60年代初作为一个思想实验来解释利他主义的进化，后来由R。道金斯绿胡子效应的主要原则是存在一个假设的基因，或一组连锁基因，表达一个可感知的性状（例如，绿色胡须），使携带者能够在其他人身上识别出这种特征，并使携带者根据其他人是否拥有这种特征而对他们表现不同（例如，具有绿色胡须的个体帮助其它“绿色胡须”个体，但不帮助没有绿色胡须的个体）。近年来，这些“绿胡子”基因在各种生物中被发现。然而，由于这些生物中的大多数都是单细胞微生物，如变形虫、酵母和细菌，我们仍然不知道这些复杂的、错综复杂的协调的、后果性的行为是否以及如何基于群体成员在其环境中的绿胡子状态而出现。火蚁，Solenopsis invicta，是为数不多的有绿胡子效应的社会性动物之一。 因此，在这个项目中，我们将以火蚁为模型系统，研究绿胡子信号与其调节的个体和集体行为之间的关系。提出了多种教育和推广计划，包括参与EcoReach计划，为K-12教师提供教育材料，在年度昆虫节和成人终身学习计划中进行推广，以及为研究生和本科生提供研究机会，包括附近的HBCU。群居动物为了群体的利益而合作。然而，这种合作行为带来了一个进化问题，因为合作者通常会遭受个体适应度的损失，以便为群体中的其他个体提供利益。研究人员提出了一个解决这个问题的潜在方案-如果一个基因表达了一个可感知的特征（例如，绿色胡须），使持有者能够在他人身上识别出这种特征，并使持有者根据拥有这种特征而对他人表现出不同的行为。该项目的主要目的是研究绿胡子信号与个体和集体行为之间的关系，它使用红色进口火蚁，红火蚁，作为模型系统调制。火蚁是为数不多的社会性动物之一，其中的绿胡子效应已被记录在案，并已确定潜在的绿胡子因素，被称为锑超基因。使用这个独特的模型系统，我们的目标是（1）了解不同类别的巢友中哪些独特的表皮化学物质构成绿胡子信号，（2）确定工人在一对一的社交互动中使用这些信号的背景，以及（3）揭示了由具有绿胡子基因型混合的工人组成的殖民地如何共同决定新兴的殖民地组织。该奖项反映了NSF的法定使命，通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Cooperation has been a longstanding evolutionary problem because cooperators suffer an individual fitness loss to provide benefits to other individuals in the group. A notable solution to this problem involves the greenbeard effect, first conceived of by W.D. Hamilton in the early 1960s as a thought experiment to explain the evolution of altruism, and later popularized by R. Dawkins. The main tenet of the greenbeard effect is that there exists a hypothetical gene, or set of linked genes, that expresses a perceptible trait (e.g., green beard), enables the bearer to recognize this trait in others, and causes the bearer to behave differently towards others depending on whether or not they possess this trait (e.g., individuals with green beard help other “green beard” individuals but not ones without green beard). In recent years, these “greenbeard” genes have been discovered in diverse organisms. Yet, because most of these are unicellular microbes, such as amoebae, yeast, and bacteria, we still know little if and how the complex, intricately coordinated, consequential behaviors emerge based on the greenbeard status of group members in their environment. The fire ant, Solenopsis invicta, is one of a few social animals in which a greenbeard effect has been documented. In this project, therefore, we will investigate the relationship between a greenbeard signal and the individual and collective behaviors that it modulates, using the fire ant, as a model system. A diversity of educational and outreach programs is proposed, including participation in the EcoReach program that provides educational materials for K-12 teachers, outreach at the annual Insectival and to a lifelong learning program for adults, as well as research opportunities for graduate students and undergraduates, including some from nearby HBCUs. Social animals work together to the advantage of their group. This cooperative behavior poses an evolutionary problem, however, because cooperators typically suffer an individual fitness loss to provide benefits to other individuals in the group. Researchers have suggested a potential solution for this problem—cooperation can evolve if a gene expresses a perceptible trait (e.g., green beard), enables the bearer to recognize this trait in others, and causes the bearer to behave differently towards others depending on the possession of this trait. The main objective of the proposed project is to investigate the relationship between a greenbeard signal and the individual and collective behaviors that it modulates using the red imported fire ant, Solenopsis invicta, as a model system. The fire ant is one of only a few social animals in which a greenbeard effect has been documented and the underlying greenbeard factor, known as the Sb supergene, has been identified. Using this unique model system, we aim to (1) learn what distinctive cuticular chemicals constitute greenbeard signals in different classes of nestmates, (2) identify contexts in which workers use such signals during one-on-one social interactions, and (3) reveal how colonies composed of workers with a mix of greenbeard genotypes collectively determine the emergent colony organization.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.