Geoscience Reference
In-Depth Information
Chapter 1
Hypothesis Testing in Ecology
CHARLES J. KREBS
Ecologists apply scientific methods to solve ecological problems. This simple
sentence contains more complexity than practical ecologists would like to
admit. Consider the storm that greeted Robert H. Peters's (1991) topic
A Cri-
tique for Ecology
(e.g., Lawton 1991; McIntosh 1992). The message is that we
might profit by examining this central thesis to ask “What should ecologists
do?” Like all practical people, ecologists have little patience with the philoso-
phy of science or with questions such as this. Although I appreciate this senti-
ment, I would point out that if ecologists had adopted classical scientific meth-
ods from the beginning, we would have generated more light and less heat and
thus made better progress in solving our problems. As a compromise to prac-
tical ecologists, I suggest that we should devote 1 percent of our time to con-
cerns of method and leave the remaining 99 percent of our time to getting on
with mouse trapping, bird netting, computer modeling, or whatever we think
important. A note of warning here: None of the following discussion is origi-
nal material, and all of these matters have been discussed in an extensive liter-
ature on the philosophy of science. Here I apply these thoughts to the partic-
ular problems of ecological science.
Some Definitions
j
Let us begin with a few definitions to avoid semantic quarrels. Scientists deal
with laws, principles, theories, hypotheses, and facts. These words are often
used in a confusing manner, so I offer the following definitions for the
descending hierarchy of generality in science:
