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

RUI：潮间带种群内微尺度空间变化的机制原因和后果

• 批准号: 1256186
• 负责人: William Dowd
• 金额: $ 45.85万
• 依托单位: Loyola Marymount University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-15 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1256186&HistoricalAwards=false
• 关键词: RUI; Mechanistic; Causes; Consequences; Micro

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.

温度在确定物种范围和驱动广泛的时空尺度上的进化模式方面发挥着关键作用。然而，温度变化的复杂空间模式可能会混淆温度在生态和进化中的作用的解释。在非常小的沿海潮间带地区，研究人员记录了个体体温的微尺度变化，这些变化可能超过整个海岸线的平均体温范围。本质上，不同的生物体以不同的方式体验相同的环境。个体之间的这种微尺度差异代表了一个重要的警告，即许多物种目前的生活接近其温度耐受极限；相反，只有一些人这样做。了解这种微观尺度变化的原因和后果非常重要，特别是在尝试预测气候变化的大规模结果时。该项目使用海贻贝作为现场和实验室研究相结合的模型系统，首先旨在回答两个机械问题：（1）体温的微尺度变化是如何产生的，以及个体是否使用行为反应来改变自己的身体根据他们最近的经验得出的温度？ (2) 热历史的变化，即最近的加热量，与个体对抗极端温度相关压力的生理能力相关吗？研究人员将首先量化体温微尺度变化的幅度和时间持续性（这是扩大规模以解决广泛的生态和进化问题之前的必要条件），然后将个体热应激的特定生化标记与其独特的热历史联系起来。最后，研究人员将解决热生理学微观尺度变化的潜在来源。个体间的变异是最近热史变异的函数，还是源于温暖与凉爽微生境中个体之间固定的生理差异，或者个体生理变异是否被其他环境因素（例如食物供应或行为？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。这项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，该团队将在现场和实验室研究中整合生物化学、行为和生物物理方法。重要的是，我们将对氧化应激机制有新的认识，该机制可能会设定物种之间和单个物种种群之间的热耐受成本和限制。通过洛约拉马利蒙特大学 [LMU，一所主要本科院校 (PUI)，拥有 21% 拉丁裔/西班牙裔人口] 和斯坦福大学之间的合作，更广泛的影响集中在本科生教学和研究的整合上。慕尼黑大学的本科生将在斯坦福大学霍普金斯海洋站进行暑期研究，极大地提高他们的专业发展和未来的职业前景。慕尼黑大学的博士后研究员将在研究、课堂教学和学生指导方面接受 PUI 特定的专业发展，同时享受斯坦福大学世界一流的资源、专业知识和优秀的现场现场。最后，研究的方法和结果将被纳入慕尼黑大学的几个本科课程中。