environment – all external conditions that influence the life of an individual or population, particularly the life of humans.

Environment ultimately determines the quality and survival of life; it is our "life support system."

physical environment – those parts of the environment that are not primarily created by humans (contrasts with cultural environment, characterized by human-made artifacts).

ecology – study of the relations between organisms and their environments.

stress – condition of intense strain or pressure that threatens the integrity of a system.

   Assigned reading in Miller textbook:  pp. 1-35