Mongolian Journal of Biological Sciences 2010 Vol. 8(2): 61-63
[Book review]
New book: The Balance of Nature: Ecology’s Enduring Myth by John Kricher, 2009,
252 pp., ISBN 978-0-6911-3898-5, Princeton University Press, hardcover, US$24.95.
As the title of this very readable book
indicates, the notion of a “balance of nature”
is one of the most persistent ideas in ecology.
The concept of balance of nature has been with
us throughout the ages ever since the ancient
Greeks and it has been accepted unquestionably
into the way of thinking about nature, especially
in Western philosophy (Egerton, 1973). It is an
ancient cultural concept, though not derived
from empirical evidence (Jelinski, 2005). High
level of interdependence of living organisms has
always fascinated us. Highly specialized species
interactions in which one species is totally
dependent on the other (obligate mutualism) for
its existence lead people to believe that there is
some sort of balance in nature. For instance,
extraordinarily close relationships such as the
ones well-documented for ant-acacia symbiosis,
fig-wasp system, and orchid-bee system have
invoked the idea of meaningful state of natural
harmony and balance since ancient times.
Even Charles Darwin (1859), in his otherwise
revolutionizing work, asserted that “Battle
within battle must ever be recurring 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.”
Evidently, like naturalists before him, Darwin
subconsciously assumed the balance of nature,
which in turn affected the way of thinking of
naturalists since his time.
This sort of explanation implies that there
is a purpose or design in the nature, a notion
that is grossly inconsistent with our current
understanding of ecological and evolutionary
dynamics. Mutualistic interactions such as
the ones mentioned above are not beautifully
balanced and stable relationships, but prone
to breakdown as theoretical models predict
(Ferriere et al., 2002; Sachs & Simms, 2006).
From modern ecological point of view, most
mutualistic interactions among species can be
viewed as reciprocal exploitation or parasitism.
From evolutionary point of view, there is just
no scientific foundation for the notion that
ecosystems evolve toward the balance of nature
(Williams, 1992).
Theoretically, ecologists have referred to the
balance of nature as the condition of ecological
systems in which a small amount of change
in some particular element is negated by a
negative feedback mechanism (Pimm, 1991).
The concept has been applied to populations,
communities, ecosystems and even the biosphere
(think of the Gaia hypothesis). However, it must
be emphasized that the theoretical concept of
mathematical equilibrium should not be confused
as the same as a balance of nature (Cuddington,
2001), as such equilibrium is plausible under a
very restricted set of assumptions, which may
or may not be biologically possible in nature.
Hypothetical ecological systems governed by
equilibrium can exhibit various interesting
behaviors (May, 1974). However, natural world,
where change and turmoil are the rule, as John
Kricher shows, is much more dynamic and
interesting.
In addition, empirical evidence mounted
against the concept of balance of nature is
enormous, making ecologists to abandon the
concept and revise the way of thinking. The
concept has been criticized recently as being
a pseudoscientific fallacy. From a number
of studies, it is clear that even predator-prey
populations that were once thought to be in
a balance via negative feedback mechanisms
display continuously varying conditions of
fluctuation and disturbance. It has even been
proposed that ecological communities are
inherently unstable due to individual differences.
Studies on climate change has uncovered a
number of positive feedback loops that may
accelerate climate change rather than reduce it,
but there is no clear negative feedback to counter
these positive feedback effects. From these
empirical studies on populations, communities
and ecosystems, it is clear that ecological
systems are in constant flux and change. At the
same time, it should be emphasized that the idea
of balance may be dependent on scale of time
and space.
Although
largely
discredited
among
ecologists (May, 1986), the concept is still
widely used in conservation activities, natural
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Boldgiv. Book review: The Balance of Nature
resources management and among a wider
population (Zimmerman & Cuddington, 2007).
The latter authors based on surveys conducted
with undergraduate students in the United States,
showed that the balance of nature metaphor is
a fuzzy, poorly defined idea that is ambiguous,
circular and polysemous. Such a lack of fixed
meaning of the concept complicates the design
of empirical tests and application of ecological
concepts to policy and management.
The book is written for broader audience,
rather than professional ecologists. Kricher
challenges the belief in the balance of nature
and nicely argues that we need to change the
way we view how natural world works. The
author explains how and why this notion of
a balance of nature has lasted for so long
and demonstrates that we as scientists and
citizens can do better by abandoning the idea
that nature is in a meaningful balance and by
accepting the dynamic nature of evolutionary
and ecological changes. The message is quite
clear. Without rejecting the complacent idea
of balance of nature, we cannot succeed
much in understanding the dynamic behavior
of ecological systems and in guiding and
formulating policies and management actions
relevant to natural ecosystems.
The Balance of Nature consists of 14
chapters. In Chapter 1, discussed why we
need to free ourselves from such notions
as the balance of nature. In fact, the author
claims that this notion is no longer helpful
to us as scientists and citizens and it is in fact
a philosophical baggage that we carry. In
Chapter 2, the author illustrates how public
perception of balance of nature plays out in
real world politics using his own personal
experience. In Chapter 3, it is explained from
the historical viewpoint that the notion is a
paradigm. In next two chapters, how ecology as
an evolutionary field, before and after Darwin,
is related to the notion of balance of nature
and how even Darwin was self-contradicted
when it comes to his theory and the age-old
paradigm. Chapter 5 outlines the history of
ecology in the last century as related to the
notion, starting with Shelford, Gleason and
Clements’ work. Chapter 7 discusses spatial
and temporal ecological dynamics and Chapter
8 outlines interplay between ecological and
evolutionary dynamics. Next chapter discusses
the egocentrism and uniqueness of life on earth
and chapter 10 illustrates the importance of
chance events. Chapter 11 takes an example of
climate system and climate change and how they
affect this notion of balance. Chapter 12 outlines
top-down and bottom-up controls of ecosystem
structure and function, concluding that food
webs are dynamic, changing and vulnerable
systems. Chapter 13, explains the importance of
biodiversity and defines biodiversity-ecosystem
function paradigm that may replace the balance
of nature paradigm. The last chapter offers how
all this translates in sustainability and natural
resource management. All in all, it is a great little
book that covers many of the related issues that
people need to be aware of.
The author claims that he knows no
professional ecologists who invoke the idea of
balance of nature today. I should emphasize
the point and urge Mongolian biologists and
scholars, especially the ones who constantly use
the term ‘balance of nature’ without giving it
any thought, to get a copy of this book and read
it. Today, it is abundantly clear that the concept
of balance of nature a trivial way of looking at
how nature works. I would like to end with a
comment made by eminent ecologist Charles
Elton (1930): “The balance of nature does
not exist, and perhaps, never has existed. The
numbers of wild animals are constantly varying
to a greater or less extent, and the variations are
usually irregular in period and always irregular
in amplitude.”
References
Cuddington, K. 2001. The “balance of nature”
metaphor and equilibrium in population
ecology. Biology and Philosophy, 16: 463479.
Darwin, C. 1859. On the Origin of Species
by Means of Natural Selection, or the
Preservation of Favoured Races in the
Struggle for Life. John Murray, London.
Egerton, F. N. 1973. Changing concepts of the
balance of nature. The Quarterly Review of
Biology, 48: 322-350.
Elton, C. 1930. Animal Ecology and Evolution.
Methuen, New York.
Ferriere, R., Bronstein, J. L., Rinaldi, S., Law,
R. & Gauduchon, M. 2002. Cheating and
the evolutionary stability of mutualisms.
Mongolian Journal of Biological Sciences 2010 Vol. 8(2)
Proceedings of the Royal Society of London.
Series B: Biological Sciences, 269: 773-780.
Jelinski, D. E. 2005. There is no balance of
nature: culture, ecology and conservation.
Human Ecology, 33: 271-288.
May, R. M. 1974. Biological populations with
non-overlapping generations: stable points,
stable cycles and chaos. Science, 186: 645-647.
May, R. M. 1986. The search for patterns in
the balance of nature: advances and retreats.
Ecology, 67: 1116-1126.
Pimm, S. L. 1991. The Balance of Nature?
Ecological Issues in the Conservation of
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Species and Communities. University of
Chicago Press, Chicago.
Sachs, J. L. & Simms, E. L. 2006. Pathways to
mutualism breakdown. Trends in Ecology and
Evolution, 21: 585-592.
Williams, G. C. 1992. Natural Selection:
Domains, Levels, and Challenges. Oxford
University Press, Oxford.
Zimmerman, C. & Cuddington, K. 2007.
Ambiguous, circular and polysemous:
students’ definitions of the “balance of
nature” metaphor. Public Understanding of
Science, 16: 393-406.
Bazartseren Boldgiv
Department of Ecology, National University
of Mongolia, Ulaanbaatar 210646, Mongolia