Ecology is an interdisciplinary science that examines interactions between organisms and their environment, and the relationship between evolution and these interactions. The interdisciplinary character of ecology allows us to understand nature by placing organisms in the context of their environment. We will explore major concepts and societal concerns in ecology, using case studies, the primary literature, observations, experiments, and the core competencies of science (data analysis, critical thinking, effective communication, quantitative reasoning, and an understanding of the link between science and society). Ultimately, we strive to understand the distribution and abundance of organisms, the very definition of ecology.