p.27-28 The population ecology model, based on the natural selection model of biological ecology, explains organizational
change by examining the nature and distribution of resources in organizations' environments. Environmental pressures
make competition for resources the central force in organizational activities, and the resource dependence perspective focuses
on tactics and strategies used by authorities in seeking to manage their environments as well as their organizations. The
three stages of variation, selection, and retention constitute a general model of organizational change, which explains how
organizational forms are created, survive or fail, and are diffused throughout a population.
p.28 Variation within and between organizations if the first requirement for organizational change, and there must also
be variations across environments if externally directed change is to occur.
p.29 selection of new or changed organizational forms occurs as a result of environmental constraints.
p.34 Retention occurs when selected variations are preserved, duplicated, or otherwise reproduced so that the selected
behavior is repeated on future occasions or the selected structure appears again in future generations.
p.34 The natural selection model is perfectly general and may be applied to any situation where the three stages are
present.
