The concept of "niche," initially borrowed by biologists from early social science, plays a central role in ecological theory... The niche... consist… - Michael T. Hannan

Hannan and Freeman examine the ecology of organizations by exploring the competition for resources and by trying to account for rates of entry and exit and for the diversity of organizational forms. They show that the destinies of organizations are determined more by impersonal forces than by the intervention of individuals by the intervention of individuals.

We argue that in order to deal with the various inertial pressures the adaptation perspective must be supplemented with a selection orientation. We consider first two broad issues that are preliminary to ecological modelling. The first concerns appropriate units of analysis. Typical analyses of the relation of organizations to environments take the point of view of a single organization facing an environment.

Natural selection, as it is actually used in evolutionary population biology, serves mainly as an optimization process. In fact, the reasoning that underlies much evolutionary biology often strikes social scientists as strongly reminiscent of neoclassical economics.