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

生物体是否具有适应当前快速环境变化(REC)的能力在很大程度上尚不清楚。我的实验室研究潜在的状态中介机制的适应能力，使有机体能够对快速环境变化(REC)做出反应。我们专注于三个逐步整合的问题，以在REC(即北极)面临的各种系统中测试这一范式：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的最佳繁殖决策？iii)个体内和个体间水平的灵活性程度如何影响种群在不断变化的世界中的弹性？更具体地说，我们实地测试了全球假设，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繁殖决策和最大化适应度方面发挥了关键的适应性作用。依靠一个高度整合的框架，我们结合生理学、行为和转录学来评估bCORT的灵活性如何产生个体和物种特有的适应反应。考虑到我们的框架，在加拿大北极工作具有很高的战略意义，因为这个生态系统的变化比地球上任何一个生态系统都快。使用三个跨越生活节奏连续体的鸟类模型，我们将长期、多年的数据集与复杂和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经验性的现场测试预测。因此，我们的研究用一个复杂的个人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，从而推动了科学的前沿。总体而言，我们正在挑战综合生态学家，以增加我们所有人如何实地测试自由生活物种投资和适应性变化的基础的机械复杂性。从进化论的角度来看，我们使用这种方法来揭示几十年来进化生态学家在很大程度上未能理解的生活史变异的机制基础。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人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，欣赏机械复杂性对于推动我们解释变化如何影响健康的理论有许多切实的优势。随着北极野生动物面临的多种环境压力迅速增加，这种可预测但灵活的方法对于评估快速变化的北极生态系统中的生物是否具有持续生存的适应能力比以往任何时候都更加重要。

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.