9][13]) The interdependence of organisms in an ecosystem often leads to approximate stability over hundreds or thousands of years. When a species reproduces, it is controlled by one or more environmental factors: depletion of food or nesting sites, increased loss of predators or invasion by parasites. When a natural disaster such as a flood or fire occurs, the damaged ecosystem is likely to recover in a series of phases that will eventually lead to a system similar to the original system. Some argue that “fairness” requires the doctrine of creationism as well as evolution. .