(RUI) From Complex Environments to Underlying Mechanisms: A Network Approach to Multi-trait Tradeoffs

为了生存和延续，生物体必须获得食物，能够繁殖，避免被吃掉，防止感染。然而，这些重要的特征中的每一个都是昂贵的维护，这可能导致特征之间的权衡。也就是说，对一种特性的投资是以另一种特性为代价的。研究人员提出了一种实验方法，研究三种重要生物特征（例如，免疫、繁殖和身体运动）之间的同时权衡，这将深入了解多特征权衡在塑造动物生存方式中的作用。鉴于性状权衡受环境影响，这些研究将在一系列模拟北美环境变化动态的操纵环境中进行。在压力条件下，对一种特质的投资可能优先于对另一种特质的投资。然而，如果个体遇到有利的环境（例如，无限制地获得食物），生殖和免疫等两种特征可能得以维持，这表明权衡可能取决于食物的可得性。粮食供应的影响往往受到可能伴随粮食供应减少的其他环境因素（例如热浪）的影响，粮食供应与温度之间的相互作用可能深刻影响权衡。这项研究将首次使用网络分析方法来描述环境变异性与动物生活史策略之间的相互作用。这种方法已被证明是研究各种现象的有力工具，例如社会互动、互联网结构以及优化工程问题的解决方案。这项研究的大部分将由来自代表性不足的少数群体的学生进行，并将辅以一项科学推广计划，旨在教育社区成员（特别是K-8学生）昆虫生物学的重要性。拟议的研究将采用一种操纵方法，在翅膀二态的蟋蟀中，研究对三个广泛重要的生活史特征的投资权衡：繁殖，免疫功能和运动。由此产生的经验数据将用于网络分析方法，通过确定几个网络指标（例如，连通性，间接性和模块化）来表征这些特征之间的动态关系。他们还将研究生命史网络与潜在生理特征网络（例如，抗氧化防御和代谢率）之间的联系。此外，他们将使用网络方法来确定两个普遍的环境约束（食物供应和温度）在多性状权衡和性状-性状相互作用中的独立和交互作用。因此，提出的研究将使用综合方法来更好地理解复杂性状系统的发展和维持。它将对多个生物学学科产生影响，包括生态免疫学、生态生理学、网络分析和生命史进化。研究人员将为学生提供广泛的研究培训，其中许多学生来自服务不足的少数群体，既代表了该地区，也代表了佐治亚南方大学（GSU）的学生群体。为了配合他们的研究目标，他们将制定一个推广计划，旨在教育年轻人关于昆虫这一重要的分类群体。他们将创建一个网站，并在GSU博物馆举办一个附带的推广展览，提供有关当地昆虫的信息。他们还将构建和传播一个教育模块，旨在满足佐治亚州教育部的绩效标准；这将包括有组织的活动，信息讲义，以及K-8学生可以用来培养科学素养的活蟋蟀。

To survive and persist, an organism must acquire food, be able to reproduce, avoid being eaten, and prevent infection. However, each of these important traits is costly to maintain, which can lead to tradeoffs among the traits. That is, investment into one trait comes at a cost to another. The researchers propose an experimental approach examining simultaneous tradeoffs among three important biological traits (e.g., immunity, reproduction, and body movement) that will provide insight into the role of multi-trait tradeoffs in shaping how animals survive. Given that trait tradeoffs are influenced by the environment, these studies will occur in a range of manipulated environments that simulate the dynamics of environmental change in North America. Under stressful conditions, investment into one trait can take precedence over investment into another trait. However, if individuals encounter favorable environments (e.g., unlimited access to food), two traits, such as reproduction and immunity, may be maintained, suggesting that tradeoffs may be dependent upon food availability. The effects of food availability are often influenced by other environmental factors that may accompany reduced food availability (e.g., heat waves), and interactions between food availability and temperature may profoundly influence tradeoffs. This research will be the first to characterize the interplay between environmental variability and animal life history strategies using a network analysis approach. This approach has proven to be a powerful tool for studying diverse phenomena, such as social interactions, the structure of the Internet, and for optimizing solutions to engineering problems. Much of this research will be performed by students from under-represented minority groups, and it will be complemented by a science outreach program designed to educate community members (particularly K-8 students) on the importance of insect biology.The proposed research will use a manipulative approach in a wing-dimorphic field cricket to examine tradeoffs among investment into three life history traits of widespread importance: reproduction, immune function, and locomotion. Resultant empirical data will be used for a network analysis approach to characterize dynamic relationships among these traits through the determination of several network metrics (e.g., connectivity, betweenness, and modularity). They will also examine linkages between the life history networks and a network of underlying physiological traits (e.g., antioxidant defense and metabolic rate). Further, they will use a network approach to determine the independent and interactive role of two universal environmental constraints (food availability and temperature) in multi-trait tradeoffs and trait-trait interactions. Thus, the proposed study will use an integrative approach to better understand how complex trait systems develop and are maintained. It will have impact on multiple biological disciplines, including ecological immunology, ecological physiology, network analyses, and life history evolution. The researchers will provide extensive research training to students, many of whom come from under-served minority groups representative of both the region and the student body at Georgia Southern University (GSU). To complement their research goals, they will develop an outreach program designed to educate young people about insects, an important taxonomic group. They will create a website and an accompanying outreach exhibition at the GSU Museum that provides information about local insects. They will also construct and disseminate an educational module designed to meet the State of Georgia's Department of Education performance standards; this will contain structured activities, informational handouts, and live crickets that K-8 students can use to develop scientific literacy.