Cultural ecology is the study of human adaptations to social and physical environments. Human adaptation refers to both biological and cultural processes that enable a population to survive and reproduce within a given or changing environment. This may be carried out diachronically (examining entities that existed in different epochs), or synchronically (examining a present system and its components). The central argument is that the natural environment, in small scale or subsistence societies dependent in part upon it, is a major contributor to social organization and other human institutions. In the academic realm, when combined with study of political economy, the study of economies as polities, it becomes political ecology, another academic subfield. It also helps interrogate historical events like the Easter Island Syndrome.
Anthropologist Julian Steward (1902-1972) coined the term, envisioning cultural ecology as a methodology for understanding how humans adapt to such a wide variety of environments. In his Theory of Culture Change: The Methodology of Multilinear Evolution (1955), cultural ecology represents the "ways in which culture change is induced by adaptation to the environment." A key point is that any particular human adaptation is in part historically inherited and involves the technologies, practices, and knowledge that allow people to live in an environment. This means that while the environment influences the character of human adaptation, it does not determine it. In this way, Steward wisely separated the vagaries of the environment from the inner workings of a culture that occupied a given environment. Viewed over the long term, this means that environment and culture are on more or less separate evolutionary tracks and that the ability of one to influence the other is dependent on how each is structured. It is this assertion - that the physical and biological environment affects culture - that has proved controversial, because it implies an element of environmental determinism over human actions, which some social scientists find problematic, particularly those writing from a Marxist perspective.