1 Samuel M. Scheiner and Michael R. Willig, eds. 1. A General ...

were clearly motivated by theory or formal models. Many papers did not invoke theory to any
extent. However, even the most empirically oriented papers were firmly seated within modern
paradigms of ecology, which itself is strongly shaped by theoretical views and constructs. The
American Naturalist favors theoretically justified papers to a much greater extent, although many
papers in that category involve evolutionary models. For example, the November and December
issues in 2008 contained 32 papers with 25 as primarily motivated or driven by theory. The 1929
(two issues each) of these two journals had almost no papers involving ecological or
evolutionary theory; only 3 of 28 in Ecology and 1 of 21 in American Naturalist were expressly
motivated by theory. A search of JStor (Ecology and Environment section) shows that the
number of papers with keywords (see legend to Figure 2.4) that indicate theoretical motivation or
links tends to increase at a faster rate than the number of papers without such a designation
(Figure 2.4; cf., slope values). Whatever the particular trends, the influence of theory on ecology
grows quickly and, very likely, faster than that of the observational component.
The growth of influence associated with the depth of analyses, improved expertise in
translating theory into lab and field research, as well as the rise of many specific theories
continues to contribute to the splitting and fragmentation ecology into areas with rather
independent existences. Growth is good, but fragmentation introduces and nurtures conceptual
incongruities that hamper ecology in my view. In support of this idea, I cite two examples: one
explicitly identifies the deficiencies due to conceptual isolation while the other shows how
unification and progress could be achieved if cross-fertilization of ideas took place. For
example, a considerable debate developed about the nature of competition among plants.
Specifically, the relationship between nutrient availability as affected by potential competitors,
allocation to root growth, and consequences of these factors for plant growth and reproduction
developed as major concerns among plant ecologists (Craine 2007). Yet, specific answers are
unlikely to interest animal ecologists and the conceptual refinements associated with them are
unlikely to apply beyond plant ecology. The second example concerns two separate research
traditions of parasite-host and predator-prey ecology. Raffel et al. (2008) argued that
developments in predator-prey ecology, such as temporal risk allocation and associational
resistance, can contribute to development of new hypotheses for parasite-host systems.
Conversely, concepts developed in parasite-host ecology, such as threshold host densities and
phylodynamics, might enrich for predator-prey ecology. Propositions such as trait-mediated
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