Examining mechanistic pathways driving the adaptive capacity of Arctic birds to respond to environmental change

检查驱动北极鸟类应对环境变化的适应能力的机制途径

• 批准号: RGPIN-2020-05507
• 负责人: Love, Oliver
• 金额: $ 4.01万
• 依托单位: University of Windsor
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=744782
• 关键词: Examining; mechanistic; pathways; driving; adaptive

It is largely unclear whether organisms possess the adaptive capacity to respond to current rates of rapid environmental change (REC). My lab studies the adaptive capacity of underlying state-mediated mechanisms to enable organisms to respond to rapid environmental change (REC). We focus on three progressively integrated questions to test this paradigm in a diversity of systems facing REC (i.e., Arctic): i) how does environmental variation shape transcriptional, physiological and behavioural flexibility to maintain individual state?; ii) how do these flexible responses translate into optimal breeding decisions that maximize fitness?; and iii) how does the degree of intra and inter-individual level flexibility influence population resiliency in a changing world? More specifically, we field-test the global hypothesis that flexibility in a state-based regulatory mechanism - baseline corticosterone - bCORT - plays a key adaptive role in mediating how environmental variation influences individual state to optimize breeding decisions and maximize fitness. Relying on a highly integrative framework, we combine physiology, behaviour and transcriptomics to assess how flexibility in bCORT generates individual- and species-specific adaptive responses. Working in the Canadian Arctic is highly strategic given our framework since this ecosystem is changing faster than any on earth. Working with three avian models that span the pace-of-life continuum, we couple long-term, multi-year datasets with sophisticated and highly integrative experimental approaches to empirically field-test predictions of individually-based, state-dependent models. As such, our research pushes the forefront of science with a complex Individual x Environment x Life History (I x E x LH) framework to test adaptive responses to REC. Collectively, we are challenging integrative ecologists to increase the mechanistic complexity of how we all field-test the basis for variation in investment and fitness in free-living species. From an evolutionary perspective, we use this approach to uncover the mechanistic underpinnings of life-history variation that have largely eluded evolutionary ecologists for decades. From an applied perspective, we increasingly rely on these quantified linkages to predict when and how environmental change will shift individuals into maladaptive scenarios that negatively impact population growth. Overall, appreciating mechanistic complexity has numerous tangible advantages for furthering the theory that enables us to interpret how change impacts fitness. With the rapid increase in the multiple environmental stressors facing Arctic wildlife, this predictive yet flexible approach is more vital than ever for assessing whether organisms within rapidly changing Arctic ecosystems have the adaptive capacity to persist.

目前还不清楚生物体是否具有适应当前快速环境变化（REC）的能力。我的实验室研究潜在的状态介导机制的适应能力，使生物体能够应对快速的环境变化 (REC)。我们重点关注三个逐步整合的问题，在 REC（即北极）面临的各种系统中测试这种范式：i）环境变化如何塑造转录、生理和行为灵活性以维持个体状态？ ii) 这些灵活的反应如何转化为最大化适应度的最佳育种决策？ iii) 个体内部和个体间水平的灵活性程度如何影响不断变化的世界中的人口弹性？更具体地说，我们对全球假设进行了现场测试，即基于状态的调节机制（基线皮质酮 - bCORT）的灵活性在调节环境变化如何影响个体状态以优化育种决策和最大化适应性方面发挥着关键的适应性作用。依靠高度整合的框架，我们结合生理学、行为和转录组学来评估 bCORT 的灵活性如何产生个体和物种特异性的适应性反应。鉴于我们的框架，在加拿大北极地区开展工作具有高度战略意义，因为这个生态系统的变化速度比地球上任何生态系统都快。我们使用三个跨越生命节奏连续体的鸟类模型，将长期、多年的数据集与复杂且高度集成的实验方法结合起来，对基于个体的、依赖于状态的模型进行实证现场测试预测。因此，我们的研究通过复杂的个体 x 环境 x 生活史 (I x E x LH) 框架来测试对 REC 的适应性反应，推动了科学的前沿。总的来说，我们正在向综合生态学家提出挑战，要求他们增加我们如何现场测试自由生活物种的投资和适应性变化基础的机制复杂性。从进化的角度来看，我们使用这种方法来揭示生命史变异的机械基础，而几十年来，这些变异在很大程度上一直困扰着进化生态学家。从应用的角度来看，我们越来越依赖这些量化的联系来预测环境变化何时以及如何将个体转变为对人口增长产生负面影响的适应不良情景。总体而言，认识到机械复杂性对于推进理论具有许多明显的优势，使我们能够解释变化如何影响适应性。随着北极野生动物面临的多种环境压力源迅速增加，这种预测性且灵活的方法对于评估快速变化的北极生态系统中的生物体是否具有持续存在的适应能力比以往任何时候都更加重要。