  The term “ecology” was coined by the German zoologist, Ernst Haeckel, in 1866 to describe the “economies” of living  forms.[1]  The theoretical practice of ecology consists, by and large, of the construction of models of the interaction of living systems with their environment (including other living  systems).[2]  These models are then tested in the laboratory and the field. (Field-work in ecology also consists of data collection that need not be inspired by any theory.)