Life on planet Earth is inundated with stress. In the following studies, I explore how stress affects the structure of communities, from plant population response to climate change, to microbial response to drought, and to student responses to active learning and resilient teaching amidst the COVID-19 pandemic. To understand how species are responding to climate change, it is vital to recognize patterns of fitness and adaptation as they respond to these stressors. In shifting montane regions, high elevation edges are areas of range expansion, where populations have low levels of genetic variation and little to no adaptation. Yet, few studies have simultaneously determined how fitness and adaptive patterns vary among populations between climate edges. In chapter one, I discuss the lifetime fitness response of the cutleaf monkeyflower, Mimulus laciniatus, an annual plant endemic to the western slopes of the California Sierra Nevada, to environmental variation in a common garden experiment. Contrary to expectation, the high garden hosted the greatest expression of genetic variation and climate adaptation across the species range. Eco-evolutionary patterns in plant species range studies, such as these, can inform our understanding of such processes as they respond to climate change. In chapter two, I synthesize general biogeographic “rules” and how they can be used to develop adaptive conservation strategies of native plant species across their ranges. I conclude this review by outlining areas of research to better our understanding of the adaptive capacity of plants under environmental change and the properties that govern species ranges. In chapter three, I take a deeper look into M. laciniatus and report the first investigation of its native microbiome and how these communities respond to a drought experiment. I found that that spatial, temporal, and environmental variation structured the fungal and bacterial endophytic community. I conclude with an initial report of the root endophyte community, their general functional implications, and ecological associations with their host. In chapters four and five, I focus on evidence-based teaching strategies in STEM curricula. In chapter five, I discuss the impact of flipping an upper-division microbiology course on student learning. I also outline the effect of a student-centered, problem-based activity on student performance. In chapter six, I list a series of pedagogical strategies for developing a resilient online classroom. I conclude with feedback from faculty from the COVID-19 remote instruction experience and suggest the most effective techniques and technologies for teaching online.