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

生物是否具有适应当前快速环境变化（REC）的能力在很大程度上是不清楚的。我的实验室研究潜在的状态介导机制的适应能力，使生物体能够响应快速的环境变化（REC）。我们将重点放在三个逐步整合的问题上，以在REC（即北极）面临的各种系统中测试这一范式：1)环境变化如何塑造转录、生理和行为的灵活性，以维持个体状态？Ii)这些灵活的反应如何转化为最优的繁殖决策，使适应性最大化？以及iii)在不断变化的世界中，个体内部和个体之间的灵活性程度如何影响人口的恢复力？更具体地说，我们实地测试了基于状态的调节机制的灵活性-基线皮质酮- bCORT -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，在加拿大北极地区工作具有高度的战略意义，因为这个生态系统的变化速度比地球上任何一个生态系统都要快。我们利用跨越生命周期的三种鸟类模型，将长期、多年的数据集与复杂、高度综合的实验方法结合起来，对基于个体、依赖状态的模型进行经验现场测试预测。因此，我们的研究以复杂的个体x环境x生命史（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。总的来说，我们正在挑战综合生态学家，以增加我们如何实地测试自由生活物种投资和适应性变化基础的机制复杂性。从进化的角度来看，我们使用这种方法揭示了几十年来进化生态学家在很大程度上回避的生活史变异的机制基础。从应用的角度来看，我们越来越依赖于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。总的来说，欣赏机制复杂性对于进一步解释变化如何影响适应性的理论有许多切实的好处。随着北极野生动物面临的多种环境压力的迅速增加，这种预测而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.