Geoscience Reference
In-Depth Information
weather is not adverse. The only way to make the predictions of this hypothe-
sis more precise is to define the background assumptions more clearly. With
respect to moose, at least five tests have been made of this hypothesis (Boutin
1992). Two tests supported the hypothesis, three did not. How do we interpret
these findings? Among my students I find three responses: The hypothesis is
falsified by the three negative results; the hypothesis is supported in two cases,
so it is probably correct; or the hypothesis is true 40 percent of the time. All of
these points of view can be defended, so in this case what advice can an ecolo-
gist give to a management agency? We cannot go on forever saying that more
research is needed.
I recommend that we adopt the falsificationist position more often in ecol-
ogy as a way of improving our hypotheses and advancing our research agenda.
In this example we would reject the original hypothesis and set up an alterna-
tive hypothesis (for example, that predation by wolves and bears together lim-
its the increase of moose and caribou populations). Indeed, we would be bet-
ter off if we started with a series of alternative hypotheses instead of just one.
The method of multiple working hypotheses is not new (Chamberlin 1897;
Platt 1964) but it seems to be used only rarely in ecology.
Recommendation 2: Articulate multiple working hypotheses for anything you
want to explain.
Two cautions are in order. First, do not assume that you have an exhaustive list
of alternatives. If you have alternatives A, B, C, and D, do not assume that if
A, B, and C are rejected that D must be true. There are probably E and F
hypotheses that you have not thought of. Second, do not generalize the
method of multiple working hypotheses to the ultimate multifactorial, holis-
tic world view, which states that all factors are involved in everything. Many
factors may indeed be involved, but you will make more rapid progress in
understanding if you articulate a detailed list of the factors and how they might
act. We need to retain the principle of parsimony and keep our hypotheses as
simple as we can. It is not scientific progress for you to articulate a hypothesis
so complex that ecologists could never gather the data to test it.
Hypotheses and Models
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A hypothesis implies a model, either a verbal model or a mathematical model.
Analytical and simulation models have become very popular in ecology. From
