RUI: Mechanistic Causes and Consequences of Micro-scale Spatial Variation within Intertidal Populations

在广泛的时空尺度上，温度在确定物种范围和驱动进化模式方面起着关键作用。然而，温度在生态和进化中的作用的解释可能会被复杂的温度变化的空间格局所混淆。在非常小的沿海潮间带区域，研究人员记录了个体体温的微观变化，这些变化可能超过整个海岸线的平均体温范围。从本质上讲，不同的生物以不同的方式体验相同的环境。这种个体间的微观尺度差异是对以下结论的一个重要警告：许多物种目前生活在它们的温度耐受极限附近；相反，只有一些人这样做。重要的是要了解这种微尺度变化的原因和后果，特别是在试图预测气候变化的大尺度结果时。本项目以贻贝为模型系统，结合实地和实验室研究，首先回答两个机制问题：(1)体温的微观变化是如何产生的，以及个体是否根据最近的经验使用行为反应来改变体温？(2)热史的变化，即最近的受热量，是否与个体对抗极端温度相关应激的生理能力相关？研究人员将首先量化体温微尺度变化的幅度和时间持久性（在扩大规模解决广泛的生态和进化问题之前是必要的），然后将个体热应激的特定生化标记与他们独特的热历史联系起来。最后，研究人员将讨论热生理微尺度变化的潜在来源。个体间变异是近期热史变异的一个功能，还是源于温暖和寒冷微生境中个体之间固定的生理差异，还是个体生理变异在野外被其他环境因素（如食物供应或行为）的变异所掩盖？个体间变异是有机体生物学中一个重要的、尚未得到充分研究的方面。本研究将把个体间的生理变化与平行的环境变化联系起来，以加深对物种应对全球变化的进化潜力的理解。为了实现这一目标，该团队将在野外和实验室研究中整合生化、行为和生物物理方法。重要的是，将获得一个新的理解氧化应激机制，可能会设定物种之间和单一物种群体之间的热耐受性成本和限制。更广泛的影响集中在通过形成洛约拉玛丽蒙特大学[LMU，一个主要的本科机构（PUI）与21%的拉丁裔/西班牙裔人口]和斯坦福大学之间的合作，本科教学和研究的整合。LMU本科生将沉浸在斯坦福大学霍普金斯海洋站的夏季研究中，极大地促进他们的专业发展和未来的职业前景。LMU的博士后研究员将在研究，课堂教学和学生指导方面获得pui特定的专业发展，同时享有世界一流的资源，专业知识和斯坦福大学的优秀现场。最后，研究的方法和结果将被纳入LMU的几门本科课程。

Temperature plays a key role in setting species ranges and driving evolutionary patterns on broad spatial and temporal scales. However, interpretation of the role of temperature in ecology and evolution may be confounded by complex spatial patterns of temperature variation. Within very small coastal intertidal areas, the investigators have documented micro-scale variation in body temperature among individuals that can exceed the average range of body temperature along an entire coastline. Essentially, different organisms experience the same environment in different ways. This micro-scale variation among individuals represents a critical caveat to the conclusion that a number of species currently live close to their temperature tolerance limits; instead, only some individuals do so. It is important to understand the causes and consequences of such micro-scale variation, particularly when attempting to forecast the large-scale outcomes of climatic changes. This project uses the sea mussel as a model system for a combination of field and laboratory studies designed first to answer two mechanistic questions: (1) How does micro-scale variation in body temperature arise, and do individuals use behavioral responses to modify their body temperature based on their recent experience? (2) Is variation in thermal history, the amount of recent heating, correlated with physiological abilities of individuals to combat stress associated with extreme temperatures? The investigators will first quantify the magnitude and the temporal persistence of micro-scale variation in body temperature (a necessity before scaling up to address broad ecological and evolutionary questions) and then link specific biochemical markers of thermal stress in individuals with their unique thermal histories. Finally, the investigators will address the potential sources of micro-scale variation in thermal physiology. Is inter-individual variation a function of variation in recent thermal history, or derived from fixed physiological differences between individuals in warm vs. cool microhabitats, or is individual physiological variation masked in the field by variation in other environmental factors such as food availability or by behavior? Inter-individual variation is an important, understudied aspect of organismal biology. This research will link inter-individual variation in physiology with parallel environmental variation to deepen understanding of evolutionary potential of species to cope with global change. To accomplish this goal, the team will integrate biochemical, behavioral, and biophysical approaches in field and laboratory studies. Importantly, a new understanding will be gained of the oxidative stress mechanisms that may set thermal tolerance costs and limits among species and among populations of a single species. Broader impacts are focused on integration of undergraduate teaching and research by forming a collaboration between Loyola Marymount University [LMU, a Primarily Undergraduate Institution (PUI) with 21% Latino/Hispanic population] and Stanford University. LMU undergraduates will be immersed in summer research at Stanford's Hopkins Marine Station, greatly enhancing their professional development and future career perspectives. A postdoctoral researcher based at LMU will receive PUI-specific professional development in research, classroom teaching, and student mentoring while enjoying access to world-class resources, expertise, and an excellent field site at Stanford. Finally, methods and findings of the research will be incorporated into several undergraduate courses at LMU.