Mediation of optimal reproductive decisions by maternal stress

人口和生态系统健康是由个人在不断变化的环境条件下最大限度地适应环境的能力推动的。由于生理功能直接调节有机体与其环境的关系，生理特征作为生活史决定和权衡的调节器是有用的，这些决定和权衡决定了适应度的变化。然而，尽管许多理论工作预测了生理和生态或环境过程之间的预期关系，但许多生理性状未能显示出一致的个体水平变异，不能普遍适用于不同的类群，或者很难在野生系统中进行实验操作。类固醇激素现在被认为在复杂性状的适应和进化中起着至关重要的作用。“压力”荷尔蒙的基线水平是调节个体内部和个体之间的投资决策的绝佳候选者，因为它们调节脊椎动物的日常和季节性能量平衡。尽管最近的研究集中在试图将压力荷尔蒙与健康直接联系起来，但这些研究往往发现不明确的结果。很少有研究被设计来解释基线压力荷尔蒙和健康之间更复杂、但可能更具生物学相关性的联系。本申请中概述的研究计划和相关项目旨在回答其中一些基本但目前尚未解决的问题。我将具体测试基线压力荷尔蒙是否：i)整合个人和环境的变异性，ii)使个人为昂贵的生活史阶段的表现需求做好准备，iii)调节适应性投资决策，从而调节健康，以及iv)通过生态和生活史水平的背景调节他们的权衡和健康效果。这类机械信息不仅对基本的探索性科学研究非常重要，而且在应用研究中越来越关键，也越来越需要，以增加我们对在北极等敏感生态系统中繁殖的个人和种群如何在面临越来越多的人类诱导压力时做出公平和反应的预测能力。

Population and ecosystem health are driven by the capacity of individuals to maximize their fitness under continuously changing environmental conditions. Since physiological function directly mediates the relationship of the organism to its environment, physiological traits are useful to study as regulators of the life-history decisions and trade-offs that shape variation in fitness. However, despite much theoretical work predicting expected relationships between physiology and ecological or environmental processes, many physiological traits fail to show consistent individual-level variation, cannot be universally applied across diverse taxa, or are hard to experimentally manipulate in wild systems. Steroid hormones are now recognized to be critically involved in the adaptation and evolution of complex traits. Baseline levels of `stress' hormones are fantastic candidates for mediating investment decisions both within and among individuals since they regulate daily and seasonal energetic balance in vertebrates. Although recent work has focused on trying to link stress hormones directly to fitness, these studies often find equivocal results. Very few studies are designed to interpret more complex, but likely more biologically relevant, linkages between baseline stress hormones and fitness. The research program and associated projects outlined in this application are designed to answer some of these fundamental, and yet currently missing, questions. I am specifically going to test whether baseline stress hormones: i) integrate individual and environmental variability, ii) prepare individuals for the performance demands of energetically expensive life-history stages, iii) mediate adaptive investment decisions, and therefore fitness, and iv) modulate their trade-off and fitness effects via ecological and life-history level contexts. This type of mechanistic information is not only very important for basic exploratory scientific studies, but it is increasingly key and needed in applied research to increase the predictive power of how we expect individuals and populations breeding in sensitive ecosystems like the Arctic to fair and respond as they face increasingly numbers of human-induced stressors.**