Concepts and problems - Nonequilibrium Ecology - page 4

History of equilibrium and nonequilibrium ecology: some
milestones in the evolution of ideas
This account concentrates on the development of some important ideas
in the equilibrium-versus-nonequilibrium debate, it does not attempt to
give a complete history of equilibrium and nonequilibrium ecology. An
early account of species equilibrium was given by Wilson ( 1969 ), and an
excellent history of population ecology is given by Kingsland ( 1995 ).
Harris ( 1986 ) provides some information on the development of equili-
brium and nonequilibrium theory in ecology, and Egerton ( 1973 ) has
given a detailed discussion of the history of the concept of balance in
nature (see also Pimm 1991 ). According to Walter and Patterson ( 1995 ),
''an uncritical and scientifically unsupported belief in the strength and central
role of competition (both interspecific and intraspecific) in evolution and
ecology is traceable to Darwin ( 1859 ) and beyond.'' Darwin wrote in his
Origin of Species ( 1859 , cited by Silverton 1980 ) that ''Battle within
battle must be continually recurring (in nature) with varying success; and
yet in the long-run the forces are so nicely balanced, that the face of
nature remains uniform for long periods of time, though assuredly the
merest trifle would often give the victory to one organic being over
another.'' The ''beyond'' Darwin includes Linnaeus, who considered an
equilibrium in nature; Adam Smith, who contributed the idea that
competition can lead to equilibrium in a community; and Malthus who
suggested that greater growth in demand than in supply would lead to
competition for limited resources (see Hengeveld and Walter 1999 for
a further historical discussion). Hutchinson ( 1948 ) takes it for granted
that stability (owing to ''self-correcting mechanisms'') is characteristic of
most ecological systems and permits their persistence. Or, as stated by
Dobshansky ( 1957 , cited by Cooper 2001 ) ''natural selection, and hence
the evolutionary process, are the outcome of competition; and therefore
are governed by density-dependent factors.'' This assumption is the basis
for Orians' ( 1962 ) opposition to the views of Andrewartha and Birch
( 1954 ), who did not recognize the predominant role of competition and
the general existence of equilibria, and who were therefore supposed
to have left ecology without a basis in the theory of natural selection.
As mentioned previously, Hutchinson ( 1948 , 1959 ) believed that com-
petition is a major factor determining species diversity and patterns in
ecological communities, but he nevertheless recognized in 1961 that
there are many more phytoplankton species in lakes than allowed by the
classical competition theory (the ''paradox of the plankton''). He suggested