6
RICHARD 5. MILLER
to a closely related group of more specialized forms - yet adaptability
does not seem necessarily to be correlated with competitive superiority.
MacArthur and MacArthur (1961) examine two ways in which species
may share the resources of a community: (1) each species may have
strict habitat preferences, feeding throughout its particular habitat on
all kinds of food, or (2) all species may share the same habitat, each
species feeding on a different food or in a different situation within the
habitat. The first alternative violates the “jack of all trades - master
of none” principle that natural selection favors the increased efficiency
of a certain amount of specialization; in the second alternative specialization has proceeded so far that time and energy are wasted travelling
from one point to another, where the particular food item or requirement is located (MacArthur and MacArthur, 1961). These authors note
that it is difficult to determine where the balance of these opposing
requirements is reached. As long as specialization leads to increased
efficiency, it will be favored by natural selection, but only up to the
point where time and energy are not wasted. While ecologists subscribe
to the general proposition that evolution proceeds as a product of
diversity and that diversity is accompanied by homeostatic mechanisms
that promote stability, considerable development and modification of
conventional competition theory will be required before species interactions can be described in terms that can be incorporated into testable
hypotheses, and which will lead to a clear understanding of the exact
nature of the mechanisms of competition and species diversity.
11. THE NATURE OF COMPETITION
In dictionary usage “competition” is defined simply as “a contest
between two rivals for the same object.” This definition is not sufficiently precise for ecological use and various attempts have been made
to qualify biological competition with respect to (1) the nature of the
contest, (2) the object of the competition and (3) the characters of the
rivals. The inconsistencies in the literature regarding the meaning and
significance of competition have been reviewed by Crombie (1947),
Solomon (1949), Birch (195T), Milne (1961) and others. In the discussions that follow I will simply employ a modified version of the definition
proposed by Clements and Shelford (1 939), namely, that “biological
competition is the active demand by two or more individuals of the
same species population (intraspecies competition) or members of two
or more species a t the same trophic level (interspecies competition) for
acommonresourceorrequirement that is actually or potentially limiting.”
Questions that arise in any consideration of the nature of competition
are: What precisely is the form of the competitive process and what
RICHARD 5. MILLER
to a closely related group of more specialized forms - yet adaptability
does not seem necessarily to be correlated with competitive superiority.
MacArthur and MacArthur (1961) examine two ways in which species
may share the resources of a community: (1) each species may have
strict habitat preferences, feeding throughout its particular habitat on
all kinds of food, or (2) all species may share the same habitat, each
species feeding on a different food or in a different situation within the
habitat. The first alternative violates the “jack of all trades - master
of none” principle that natural selection favors the increased efficiency
of a certain amount of specialization; in the second alternative specialization has proceeded so far that time and energy are wasted travelling
from one point to another, where the particular food item or requirement is located (MacArthur and MacArthur, 1961). These authors note
that it is difficult to determine where the balance of these opposing
requirements is reached. As long as specialization leads to increased
efficiency, it will be favored by natural selection, but only up to the
point where time and energy are not wasted. While ecologists subscribe
to the general proposition that evolution proceeds as a product of
diversity and that diversity is accompanied by homeostatic mechanisms
that promote stability, considerable development and modification of
conventional competition theory will be required before species interactions can be described in terms that can be incorporated into testable
hypotheses, and which will lead to a clear understanding of the exact
nature of the mechanisms of competition and species diversity.
11. THE NATURE OF COMPETITION
In dictionary usage “competition” is defined simply as “a contest
between two rivals for the same object.” This definition is not sufficiently precise for ecological use and various attempts have been made
to qualify biological competition with respect to (1) the nature of the
contest, (2) the object of the competition and (3) the characters of the
rivals. The inconsistencies in the literature regarding the meaning and
significance of competition have been reviewed by Crombie (1947),
Solomon (1949), Birch (195T), Milne (1961) and others. In the discussions that follow I will simply employ a modified version of the definition
proposed by Clements and Shelford (1 939), namely, that “biological
competition is the active demand by two or more individuals of the
same species population (intraspecies competition) or members of two
or more species a t the same trophic level (interspecies competition) for
acommonresourceorrequirement that is actually or potentially limiting.”
Questions that arise in any consideration of the nature of competition
are: What precisely is the form of the competitive process and what