Recognition of the Possible: An Advantage of Empiricism in Ecology

In many sciences there exist unpredictable phenomena, phenomena that for one of several reasons are deduced to be unpredictable from a current paradigm theory. In ecology, the long-term abundance of a given species in an ecosystem is an example of an unpredictable variable. From the theory of the ecosystem as a highly interactive complex of species in which rare species can potentially become abundant, we can deduce that species-based, systems analysis modeling cannot make long-term forecasts of species abundance. From the theory of evolution by natural selection it can be further deduced that no theory, regardless of its structure, can make these predictions. Because our general theories are informal and often only implicit, deductions such as those I have drawn may be incorrect. Nevertheless these deductions give compelling reasons for applied ecologists to pay serious attention to our general ecological theories and their consequences. They also suggest that empirical ecologists who concentrate their efforts on predictable properties of ecosystems remain on firm theoretical grounds and are not merely avoiding the more difficult problems.Key words: ecological theory, empiricism, prediction