Ecology: Definitions Ecology: The scientific study of the interactions between organisms and their environment that determines the distribution and abundance of organisms Ecology is a science Environmentalism is a cause Conservation Biology is the integration of these two: using science to support a political cause Population ecology: experimental field approach: natural populations manipulated to test specific predictions arising from controversial ecological theory Organismal ecology: studies how an organism?s structure, physiology, and (for animals) behaviour meet environmental challenges Population: all the individuals of the same species within an ecosystem Population ecology focuses on factors affecting how many individuals of a species live in an area