Environmental Engineering Reference
In-Depth Information
tains two plant species and six insect species and the high diversity area has
three plant species and eight insect species. An answer to our initial ques-
tion is that insect species diversity increases with plant species diversity.That
is, there appears to be a positive relationship between plant and insect species
diversity.
Induction here led to the discovery of an association between two kinds
of observations or variables (known as correlation). In our particular exam-
ple, a positive correlation implies that plant species diversity is somehow re-
lated to insect diversity.There is, however, one important hitch. Although
we have identified a relationship, we still haven't explained
why
higher plant
species diversity is associated with higher insect species diversity. Formu-
lating explanations for observed phenomena lies within the next phase of
science methodology.
Retroduction
Retroduction ascribes a reason—or technically an
hypothesis
, because the
reason is only proposed and thus not yet validated by a scientific test—for
the association or trend observed through induction.This is perhaps the
most creative aspect of science.The scientist uses his or her imagination in
combination with accumulated knowledge about nature to explain why we
see a particular phenomenon or trend.This phase of science often leads to
those new ideas or theories that form the important conceptual foundation
for a discipline.
In our example, one plausible explanation for the positive correlation be-
tween insect species diversity and plant species diversity is this:A greater va-
riety of plant species provides a greater variety of resources for insect species
with different food requirements.Therefore habitats rich in plant species
offer a host of food resources to support a rich variety of insect species.
This may seem like a satisfactory answer. Nonetheless, it remains
untested. So, we don't know if our particular explanation is the correct one.
Without testing the hypothesis, the knowledge we acquire from this stage
can be shaky. One must be mindful that all hypotheses, however well con-
ceived, could be flatly wrong. Serious negative consequences can ensue if
we stopped at this stage and applied this knowledge to policy and manage-
ment (Romesburg 1981).The danger here is that we may create significant
changes to ecosystems before we really know whether or not the hypoth-
esized causal relationship exists in nature. Hypotheses must be tested before
applying them widely to environmental problem solving because equally
