In contrast with the long-held ethnobiological tradition conceptualizing knowledge systems as static and continuous, in recent decades the discipline has reemerged with a focus on the dynamic character of local environmental knowledge (LEK). This new era in ethnobiology started with studies documenting the erosion and loss of local knowledge systems around the world and is now shifting toward the understanding of the ability of LEK systems to adapt to new social-ecological conditions. Nourishing from resilience theory, new ethnobiological research points toward the adaptive capacity of LEK systems, also addressing the structural constraints of LEK adaptation in the face of ever-encroaching global environmental change. This chapter provides a historical view of the literature addressing change and adaptation of LEK systems and identifies critical tasks for future ethnobiological research, as the discipline keeps expanding into new understandings of the changing human-biota relationships in novel social-ecological scenarios.