THE CHALLENGE OF "THE NEW
ECOLOGY"
In the canon of environmental ethics, Aldo Leopold wrote
Genesis I-1: "A thing is right when it tends to preserve the
integrity, stability and beauty of the biotic community; it is wrong
when it tends otherwise."(1) However,
ecology is a science, and environmental ethics is pursued most
scrupulously by philosophers. And to scientists and philosophers,
there is no holy text. Even Leopold's maxim is fair game for
circumspect analysis, evaluation and confirmation. In fact, the
presuppositions of Leopold's maxim have been relentlessly
scrutinized, to the point that, if you are to believe many of the
"new ecologists," a literal reading of that maxim is about as
scientifically respectable as a literal interpretation of Genesis.
Gone is the easy assurance of "the integrity and stability of
nature." Even "community," that cornerstone of the Leopoldian land
ethic, is in disrepute. The "beauty" of nature, a concept saturated
with subjectivism and evaluation, never has cut much scientific ice.
"Balance" and "equilibrium" are rarely heard today in respectable
eco-scientific circles, and according to some radical critics of
classical ecology even the system of "ecosystem" is
suspect.
Attacks on the once-cherished concepts of ecological
stability, equilibrium, balance and integrity come from
both within and beyond the ranks of biological science. For example,
the biologist, Michael Soulé writes:
"... the idea that species live in integrated communities
is a myth.. Living nature is not equilibrial -- at least not on a
scale that is relevant to the persistence of species. Nor do
homeostatic systems such as Gaia buffer life on a relevant
spaciotemporal scale... Current ecological thinking argues that
nature at the level of local biotic assemblages has never been
homeostatic. The principle of balance has been replaced with the
principle of gradation -- a continuum of degrees of
disturbance."(2)
So what then remains of "ecology"? According to Kristin
Shrader-Frechette and E. D. McCoy, ecology fails as grand and
comprehensive theory: it can not predict events, nor can it explain
deductively -- i.e., "down" from general theory to particular events.
They observe that
... ecologists have defined and used two of the concepts
most basic to community ecology -- "community" and stability" --
in ambiguous and often inconsistent ways... Ecologists are
likewise divided on what structures communities or holds them
together.
Accordingly, they argue, we are thus best advised to confine our
ecological attention to empirical "natural -history knowledge" and
"individual case studies." [8]
One of the most carefully articulated and thoroughgoing critiques
of "classical ecology," is by philosopher Mark Sagoff and was
published in the March, 1997 issue of The College of William and
Mary Law Review.(3) A
pre-publication draft of that paper was presented to The Global
Integrity Project at its Montreal meeting in October, 1996.(4)
SAGOFF'S CRITIQUE OF "THEORETICAL
ECOLOGY"
In Sagoff's lengthy and scrupulously argued critique, the
following nine points are conspicuous:
1. The principles of theoretical ecologists can not predict
and are not falsifiable, and thus, by implication, they are not
confirmable and thus are devoid of scientific significance.
[888]
2. "Ecosystems" are, in fact, devoid of
system. Put bluntly, "the terms 'eco'
and 'system,' when conjoined, constitute an oxymoron" [923]
This is because "the ecosystem as an object of scientific inquiry is
just a pointless hodgepodge of constantly changing associations of
organisms and environments." [901]
3. Nature is in constant change: In support of this
claim, Sagoff quotes the biologist, Daniel Botkin: "Wherever we seek
to find constancy, we discover change... [We find] that
nature undisturbed is not constant in form, structure, or proportion,
but changes at every scale of time and space."(6)
4. Ecology lacks a classification system:
"If the term "ecosystem" or "community" [is] to
be predicated on a collection of objects over time, there must be
a way of telling when this collection is the same community or
ecosystem and when it has evolved or changed into a different one.
After all, ecosystems never die; they just fade into other
ecosystems. Accordingly, in order to predicate properties of
ecosystems, we must have a classification scheme that allows us to
determine when the object of study remains the same ecosystem even
though its qualities change, and when an ecosystem of another time
replaces it.... This requirement is an important conceptual
condition for doing ecology because otherwise crucial notions,
such as resilience or stability, could not have any meaning."
[894]
5. Ecology lacks "baselines," -- norms from which to
assess deviations. Thus theoretical ecologists are unable to address
such questions as these:
"Where in the flux of a biological community do we take a
'snapshot' and say 'here it is in equilibrium' or 'here it has
integrity' or 'now we have reached the carrying capacity of the
land'? Is the ecosystem developing toward a 'healthy' condition,
is it now 'healthy,' or is it falling apart" 'What is the
criterion?' These questions are unanswerable because we do not
know which qualities of ecosystems are the identifying, genuine,
or defining ones." [900]
6. "There are no general truths about ecosystem
organization ... anything is possible consistent with the laws
of physics in nature. If ecosystems are unstructured, transitory, and
accidental in nature, it would seem to follow that no general
economic or utilitarian grounds exist for protecting them from
change." [931-2]
7. Nature has no logos and
it has no telos:
"...nature is going nowhere, has no "integrity" or
"well-being" of its own [logos], and is utterly
devoid of any meaning, order, purpose, or end
[telos]. If contingency, historical accident,
turmoil, disturbance, and path-dependent chaotic randomness
comprise the only rules that govern the course that ecosystems
follow -- or if the terms "eco" and "system," when joined,
constitute an oxymoron, as suggested by the "new paradigm" -- then
it is just one damned thing after another out there. Nature does
not know (it has no logos) and Nature does not care (it
has no telos)." [923] (Note the ambiguities
raised in the final sentence: logos first as "design" and
then as "knowledge," and telos first as "purpose" and
then as "caring." These will prove significant later in our
analysis).
8. Ecosystems are unaffected by organic evolution.
"Ecosystems could not possibly have acquired [their
allegedly] wonderful organization through evolutionary
processes. This is because natural selection operates only on
creatures that breed true, that is, creatures that enjoy genetic
inheritance. Ecosystems do not reproduce, possess genomes, or
breed true; heredity is nothing to them. Accordingly, they are not
subject to evolution. We should have to account for any order,
design, harmony, or structure we impute to ecosystems by appealing
to some cause other than evolution. The only other cause is
agency, human or Eternal." [957]
9. Value is grounded in individual organisms and (at most)
species, not ecosystems.
"It is the unlikelihood, not the perfection, of the
living world that amazes us; the improbability of every plant and
animal leads us to treasure its existence. Species, even those not
yet named, command our moral attention because they have emerged
through a billion-year-old toil of evolution... This ethic of
preservation, which frankly regards creatures as miraculous in
their improbability, values every species as intrinsically
marvelous and worthy of respect and admiration, but does not
pretend that it fits into a larger design or plan."
[966]
With challenges such as these, we have clearly come a long way
from the confident quasi-scientific rhetoric of the first Earth Day
-- from such bold pronouncements as Barry Commoner's four "Laws of
Ecology:" (7)
1. "Everything is Connected to Everything Else."
2. "Everything must Go Somewhere." ("There is no 'away.'")
3. "Nature knows best."
4. "There is no such thing as a free lunch."
IMPLICATIONS FOR ENVIRONMENTAL
ETHICS
Mark Sagoff's critique of ecology strikes at the heart of most
(but not all) contemporary schools of environmental ethics. (The
exceptions would be the "animal rights" approach, "strong"
anthropocentrism, and Sagoff's "intrinsic valuation" of individual
organisms). In particular:
-
Most vulnerable is "the land ethic" of Aldo Leopold, who, in
that most quoted of all environmental maxims, wrote: "a thing is
right when it tends to preserve the integrity, stability and
beauty of the biotic community. It is wrong when it tends
otherwise."(7) From this, Sagoff
would strip integrity, stability and community,
leaving only beauty -- but a beauty, not of the whole,
but of the component organisms and species.
-
Gone too is "Muir's maxim:" "You cannot disturb a pasque
flower without disturbing a star" -- an affirmation that "all
things are connected." Instead, we have a disconnected
"hodge-podge" of independently co-existing organisms.
-
Furthermore, "the new ecology" challenges the notion that
"integrity" is a recognizable condition in ecosystems, and thus a
meaningful goal of environmental policy. "An ecosystem in a state
of integrity," writes Laura Westra, "comprises self-organizational
processes both in its internal relations and its external ones
with adjacent ecosystems."(9) To
the contrary, Sagoff rejoins, "nature has no 'integrity' or 'well-being' of
its own, and is utterly devoid of any meaning, order, purpose, or end."
[923]
-
And if Sagoff is correct, the attention of conservationists
and preservationists should be directed, not to ecosystems, but to
individual organisms and to species. In particular, "wilderness
preservation" is a meaningless and pointless enterprise.(8)
The implications of "the new ecology" for public environmental
policy are profound. Gone is a justification for wilderness
preservation, much less of wilderness restoration. For if ecosystems
are in constant but aimless flux, then attempts to "preserve" (i.e.,
protect from change) an allegedly "pristine" state, are "contrary to
nature."(9) And proposals to "restore"
wilderness raise the question, "restore to what condition?"
If there is no definable "baseline" condition that describes
"wilderness," then that question has no answer and thus "restoration"
policy has no foundation or meaning. Finally, endangered species
legislation loses its justification for, according to Sagoff,
extinction is of no great practical significance. After all, he
writes, "... no extinction of any species in the United States seems
thus far to have altered the capacity of the ecosystems to provide
these services. The reason may be that for any species that is lost,
tens, hundreds, or thousands of others are ready, willing, and able
to perform the same functions and services valuable to human beings."
[904] And, human beings aside, "no prima facie, general, or
theoretical reason can be given, then, to suppose that the extinction
of species now feared will in any meaningful way harm nature, because
nature, having neither design or direction, is not the sort of thing
that can suffer harm."(10)
[967]
To be sure, Sagoff is not indifferent to the loss of species
which, he insists, "commands our moral attention..." (And thus I
wrote, above, of extinction as having "no practical significance,
though to Sagoff it would be of moral significance).
Accordingly, Sagoff endorses an "ethic of preservation," which
"values every species as intrinsically marvelous and worthy of
respect and admiration." [966] How, then, are we to act in
conformance to this "ethic of preservation?" By preserving habitats
and ecosystems? Only if such preservation serves as effective means
to the end of protecting the species. The ecosystems themselves, he
assures us, have no intrinsic value. So if, for example, the
California Condor would be safer in a zoo or refuge than in its
"natural" habitat, so be it. There remains no further objection to
bringing in the bulldozers and "developing" the Los Padres National
Forest.(11)
THE ECOLOGIST'S
REBUTTAL
So what remains of ecology, and is it enough to lend comfort to
those still attracted to the Leopoldian Land Ethic or, for that
matter, an ethic of "integrity"? I believe there is. But while I
believe much of value can be salvaged from the older notion of
"nature as community," it would be a mistake to assume that this
older view can be rescued intact from these critics. Ecology will
never be the same -- nor should it be.
I offer nine fundamental points of rebuttal to the new critics in
general, and to Sagoff in particular:
-
These challenges are both persuasive an original.
Unfortunately, many of the challenges that are persuasive are not
original, and many that are original are not persuasive.(12)
-
Some of the challenges are plainly false: in particular, the
charge that ecological theory is non-falsifiable,
non-predictive, and devoid of an operational classification
system.
-
Ecosystems are, in fact, systems.
-
Ecosystems are sensitive to natural selection among their
components, and thus exhibit the kind of systemic structure,
integrity and resilience that is found among organisms.
-
Sagoff's charge that "nature does not know ([because
it] has no logos) and does not care ([because it] has
no telos) is true -- and irrelevant to the "moral uses of
ecology.
-
Traditional ecologists did not (or at least did not need to)
claim that "equilibrium" and "balance" were perfectly exemplified
in nature. Rather, these are "ideal types," of the sort that are
well known in such "hard sciences" as physics.
-
Ecosystems can be recognized to be, in some
non-normative sense, "better" or "worse" than others. ("Healthier"
if you prefer.). Thus there may well be good reason to prefer
"natural" ecosystems to those "cultivated" by human societies.
-
The ultimate inscrutability of ecosystems, suggested by the
new ecologists, far from undermining ecological morality, serves
to strengthen it.
-
Because virtually all "deconstructionist ecologists" accept
the theory of evolution, they must presuppose some degree of
design, order, constancy and resilience -- i.e., some
system in ecosystems.
1. That which is persuasive is not original; that
which is original is not persuasive..
Persuasive but not original: "Wherever we seek to find
constancy," writes Daniel Botkin, "we discover change." Perfect
equilibrium and balance are nowhere to be found in nature. "Nature is
in constant flux."(13)
But of course nature is in constant flux. What
self-respecting biologist would deny this! It's called "evolution."
But this does not preclude us from recognizing significant
differences in the scale of change. After all, species
change through evolution. But this does not forbid biologists from
utilizing the concept of species, nor to develop a taxonomy
of species. In fact, without that taxonomy, the theory of evolution
might never have been developed.
The issue deserves closer scrutiny. And so we return to Botkin --
in particular, his account of the biotic history of the history of
the "Boundary Waters" region of northern Minnesota and southern
Ontario:
... the last glaciation was followed by a tundra period
in which the ground was covered by low shrubs now characteristic
of the far North, as well as reindeer moss and other lichens and
lower plants. The tundra was replaced by a forest of spruce,
species that are now found in the boreal forests of the North,
where they dominate many areas of Alaska and Ontario. About 9,200
years ago the spruce forest was replaced by a forest of jack pine
and red pine, trees characteristic of warmer and drier areas.
Paper birch and alder immigrated into this forest about 8,300
years ago; white pine arrived about 7,000 years ago, and then
there was a return to spruce, jack pine, and white pine,
suggesting a cooling of the climate. Thus every thousand years a
substantial change occurred in the vegetation of the forest,
reflecting in part changes in the climate and in part the arrival
of species that had been driven south during the ice age and were
slowly returning. Which of these forests represent the
natural state. If one's goal were to return the Boundary Waters
Canoe Area to its natural condition, which of these forests would
one choose? Each appears equally natural in the sense that each
dominated the landscape for approximately 1,000 years, and each
occupied the area at a time when the influence of human beings was
non-existent or slight."(14)
Botkin asks, rhetorically, "which of these forests represents the
natural state," as if to suggest that, due to the multiplicity of
states thus described, there is no so-called "natural state." But
this very passage suggests a non-rhetorical rebuttal: "the
natural state" is that which is brought about by the climatic
(and other) conditions that prevail at the time. That "state" is
established by (relatively) undisturbed nature, and then is succeeded
when natural circumstances change.
Put bluntly, I suggest that a critical examination of this passage
will yield us less here than meets the eye, and less than Botkin
intended. For what is Botkin asserting that any informed "equilibrium
model ecologist" such as Odum or Leopold, would deny? All these
ecologists are well aware that North America undergoes periodic
recurrences of ice ages and other climatic changes, measured in tens
of thousands of years. But "balance," "equilibrium" and "resilience"
are conditions posited within stable abiotic (e.g.,
climatic) conditions -- or as the popular phrase has it, "all else
being equal." Granted, "all else" is never completely "equal,"
and so classical ecologists write of "tendencies" toward balance,
equilibrium and resilience. Still, these ecosystemic concepts are
quite enough to supply us with explanations of the past and
predictions for the future.
To illustrate this point, let us shift our attention from the
Boundary Waters to the Pacific Northwest.
About ten years ago, on a flight from Los Angeles to Seattle, I
looked out the window upon an unforgettable scene of utter
devastation. It was, of course, the area immediately north of Mount
St. Helens. On that vast mantle of tan pumice and fallen logs, there
was no apparent sign of life. And yet, a layman might surmise, and a
professional historical-ecologist would confirm, that in another five
hundred years (absent climate change or massive human intervention),
the area would look very much as it did on that early morning of May
18, 1980, moments before the north face of the mountain exploded.
Through known stages of ecological succession, it will once again
become what it was before: a northern conifer rain forest -- not a
tundra, or a tropical rain forest, or a prairie, or a Sonoran
desert.
How would we know this? We know by studying neighboring areas up
and down the Cascade Range, where other volcanoes, at determined
dates in the geologically recent past, caused similar devastation.
There we find, at this moment, the various stages of succession and
recovery. And in those regions untouched by a recent eruption or fire
or logging, we encounter an identifiable "type" of integrated life
community -- an ecosystem -- very much as one would have
encountered two-, three-, or four-hundred years ago. This is what
ecologists correctly call a "climax stage."
Would the acute botanical eye of a time-traveling Prof. Botkin
detect differences at hundred-year intervals? Of course. But once
again, no one suggests that "balance, equilibrium and resilience" are
ever perfectly exemplified in nature. Nor is a "climax community"
ever completely static. These concepts, after all, describe
"tendencies." But surely, these concepts are scientifically useful,
as they describe significant conditions and differences. (We will
expand upon this point in "Objection 4," below). True, there is no
"perfect balance and equilibrium" in nature. Still there is a
significant difference between the "imbalance and disequlibrium" of
the Pacific Northwest forests of, say, four hundred years ago, and
that of the same forest today as it is assaulted by Weyerhauser's
chain saws. The former is measured on a time scale of millennia,
while the latter is measured in years.(15)
To ignore such contrast in scale would be comparable to dismissing
the concept of "disease" in medicine, with such an argument as this:
"you say that so-called 'disease' causes changes in the organism?
Well, so too does aging? In fact, everyone's organic condition is in
constant flux. So what's the difference?" Similarly, "the
biodiversity crisis" is casually dismissed with the remark, "why
worry about extinction? After all, extinction is a natural process."
In all these cases the difference is degree of change -- and it is a
difference that is ignored at the peril of both the patient and a
civilization.(16)
No doubt, the concepts of ecological balance and stability have
been exaggerated in the hands and heads of some uncritical writers
and activists, and some unfounded ideology has emerged from these
abuses. We are thus indebted to Daniel Botkin and others for
supplying a much-needed antidote. But is it not possible that Sagoff
has taken an overdose of that antidote, as he proclaims that the term
"ecosystem" is "oxymoronic," and that so-called "natural communities"
are merely "random, accidental, contingent and purposeless
collections of biological flotsam and jetsam." [931n]
Original but not persuasive: In a breathtaking feat of
creative imagination, Sagoff associates "theoretical" or ("old")
ecology -- a position defended by renowned biological scientists --
with "the design argument" and even with "creation science." He
writes:
Theoretical ecology .. represents the triumph of Great
Chain of Being cosmology in our time... The term 'evolution,' as
employed in theoretical ecology, may be understood as a stand-in
or proxy for God as the designer of ecosystems. If this is so,
then to the extent that ecology attributes logos and
telos to nature, there may be little reason to
distinguish it from Creation Science.". [959-60]
And in his dismissal of Paul Ehrlich's well-known "rivet popping"
analogy, (19) Sagoff writes:
The implication of [this] analogy is that
ecosystems are designed to support human existence and that each
species has a (sometimes redundant) place in that design.
Humanity, in that design, crowns creation, and all other species
are artfully placed, like rivets in a wing or links in a chain,
supporting homo sapiens. [962]
I am sure that Prof. Ehrlich would find this a bizarre
interpretation of his analogy, as do I. The rivet story was, after
all, an illustrative figure, not an argumentative device. Never have
I read nor heard of Ehrlich, or any scientifically trained ecologist
for that matter, drawing such "theological implications." Nor does
the concept of "ecosystem as system" require such an analogy
or bear any such implications. Bio-scientists normally treat
ecosystems naturalistically. Thus by posing the question,
"What are ecosystems designed to do?," Sagoff is simply begging his
assumption that ecologists are crypto-theologians in search of a
"designer." [962] In fact, few ecologists believe that
ecosystems are "designed," still less that they are "designed" for
our benefit -- nor do they need to. Quite the contrary, they argue
that the widespread attitude in industrial civilizations that the
Earth is a cosmic vending machine "designed" for our benefit, has
caused homo sapiens much grief in the past and is leading us
toward catastrophe in the future. As James Lovelock once said of his
Gaia hypothesis, to suggest that the Gaia operates to make
the planet hospitable to life, does not necessarily mean hospitable
to human life.
2.
Some of the challenges are plainly false:
in particular, the charge that ecological theory is non-falsifiable,
non-predictive, and devoid of an operational classification
system.
Falsifiability: Sagoff correctly points out that
scientific hypotheses and theories must be falsifiable: they
must, that is, they must describe a world that is identifiably
different from what the world would be like if the scientific claim
were false. [949] Thus a scientifically sound theory yields
predictions which, by implication, "rule out" innumerable conceivable
states-of affairs.
Consider, for example, general relativity theory. If the
established alternative theory of Newton were correct, light from a
distant star passing near the sun during an eclipse would be
unaffected. Einstein's equations, to the contrary, predicted
deflection of the light due to "space-time distortion," and then
placed precisely the apparent location of the star during the
eclipse. The prediction thus, by implication, ruled out all
alternative apparent locations. Had the light source appeared at any
other apparent location, the theory would have been falsified.
Similarly, there are numerous imaginable fossil depositions, or
DNA sequences, or anatomical structures, and so forth, which, if
discovered, would refute organic evolution. Exhaustive field and
laboratory research has failed to find any of these.
In contrast, consider two creationist "theories" of the origin of
fossils that I was taught as a child: (a) God placed them in the
ground to test our faith, and (b) Satan placed them in the ground to
lead us astray. Each theory is non-falsifiable, since, no matter what
we might find in nature, we can assume, a priori, that God
or Satan (take your pick) has superior capabilities to "test" or
"deceive," as the case may be. Put another way, neither of these
"theories" "explain" fossils; rather, they attempt to "explain them
away." Presumably, Sagoff's complaint against "theoretical
ecologists" is that reports of failure to find "integrity" in
ecosystems, is routinely followed by the retort, "well, you just
haven't looked hard enough" -- i.e., that these ecologists give no
hint of what it would be like for their theories to be false, and
thus they interpret this self-defined "failure" to refute as
confirmation of their theory.
Contra Sagoff, it appears, in numerous cases, that
ecological theory is quite falsifiable -- i.e., that it describes a
world, that could readily be found to be otherwise if the theory were
false. Consider for example, "succession theory." Any time someone
returns, contrary to that theory, with a confirmable report of a
meadow being replaced, first by shade tolerant conifers, then
succeeded by shrubs and "junk wood" such as aspens and birches -- at
such a time, standard succession theory will have been falsified and
refuted.
Or consider Liebig's law of "limiting factors." One can describe a
Julian-Simon type world in which an ecosystem, or a species
population within, having utilized all available amounts of a
necessary nutrient, then go about and find some suitable "substitute
resource." Nature simply does not, and can readily be shown not to,
work that way.
Finally, there are all kinds of ways that energy flows through
ecosystems might be imagined to violate fundamental thermodynamic
laws. If, for example, these laws did not apply to ecosystems, the
numbers or the biomass of predators in proportion to their prey would
be found to be different than they are in fact.
The predictability of ecological assertions follow
directly from their accordance with the falsifiability criterion.
Thus we can correctly predict the succession of tree communities in a
clear-cut or burnt-over forest. And, once we have ascertained that
oxygen is the limiting factor in an aquatic ecosystem, we can predict
the consequences of oxygen deprivation.
Finally, classificatory systems: Sagoff points out that
"in order to predicate properties of ecosystems, we must have a
classification scheme that allows us to determine when the object of
study remains the same ecosystem even though its qualities change,
and when an ecosystem of another time replaces it." [894]
In this criticism of "the old ecology," Sagoff is employing "the
spectrum argument" (also known as "the argument of the
beard"(20)); namely, the argument
that from the absence of clear lines of demarcation along a
continuum, one concludes that there is no difference in extremes in
that continuum. Applied to the case at hand, it is admittedly true
that absent catastrophic events such as fires, floods or volcanic
eruptions, ecosystems change gradually. Thus, the "boundary lines"
(if any) between ecosystemic types are indistinct and somewhat
arbitrary. However, it does not follow from this that an ecological
classification scheme is unattainable. The ecological application of
the "spectrum" fallacy is compelling: When settlers find a forest,
and then clear-cut it to make way for monocultural fields, at which
particular tree-felling does the ecosystem change from forest to
field? None? Then, the argument goes, there is no difference between
a forest and a field. Clearly a fallacy.
In point of fact, ecology does have a classification scheme. The
distinction between producers, consumers and
decomposers is as secure in ecology as the distinction
between igneous, sedimentary and metamorphic rocks
in geology -- and as fundamental to the structure of the science. In
addition, it is noteworthy that these concepts are defined in terms
of functions within a system -- the ecosystem. And
while Daniel Botkin might disagree, there is also a less-firm but
nonetheless essential classificatory distinction between transitional and
climax communities. The former are
characterized by internal mechanisms of relatively rapid change often
following sudden catastrophic interventions (such as fire or volcanic
eruption), while the latter are characterized by slow change brought
on by moderate external perturbations. However, as the "new
ecologists" never tire of reminding us (while few of the "old" have
ever disagreed), so-called "climax communities" are never totally
static.
Notwithstanding all this, Sagoff insists that ecology is a
quasi-science since "there are no universal patterns or determinate
relationships among the typical constructs of ecological theory..."
[949] Really? What about the universal pattern that describes
the relationship between producers, consumers and decomposers? What
about the unidirectional flow of energy and nutrients "up" the trophic pyramid? Wolves "universally" hunt, never graze -- even when
there is no game to hunt, in which case they starve. Why is this? Because of the digestive system of canids, which has evolved to its
state due to the ecological niche that the organisms have come to
occupy. The ecosystem has shaped the genome of the wolf which,
reciprocally, has implications for the system. All this is described
by rules and concepts of ecology which are falsifiable -- i.e.,
might be recognizably false in a world differently ordered (e.g., a
"Star-Trek" world of "shape-shifter" and "genome-shifter" organisms
-- a conceivable world, but not our world).
Having said all this, we must acknowledge that Sagoff's criticisms
are not without some merit. As we shall point out in the conclusion,
while some ecological theories are falsifiable, others are just
marginally so. And while there is an identifiable classificatory
scheme in ecology, there is room in the science for considerable
improvement in conceptual clarification and taxonomy.
3. Ecosystems are, in fact, systems.
Perturbations to parts of ecosystems affect all or most other
parts. In that finest ecological speech never uttered, Chief Seattle
(allegedly) said, "all things are connected." And Garrett Hardin:
"You can't do just one thing." Yet Sagoff would have us believe that
"the terms 'eco' and 'system,' when conjoined, constitute an
oxymoron." [923]
If we are to determine whether or not ecosystems are "systemic,"
we must first define "system." I propose the following definition: "a
system is a collection of identifiably separate entities
acting in dynamic interaction to perform tasks in concert that can
not be accomplished separately." Accordingly, a watch and a computer
is a system -- also a football team, a thermostat and furnace, and,
as I hope to demonstrate, an ecosystem.
Consider first, the football team. A well-executed play
accomplishes, through the integrated activity of the team, what no
single player can do by himself. A completed forward pass is, by
definition, a "binary" act (involving the quarterback and receiver),
and it takes place in the context of blocks, fakes, etc., involving
all eleven members of the team. By contrast, a broken play is a
system in disintegration, and it is accomplished through the
successful systemic integration of the defense.
The thermostat and furnace, acting together, constitute a simple
"negative feedback system." We all know the "loop" mechanism: furnace
on > heat rises > thermostat off > furnace off > heat
falls > thermostat on > furnace on -- and thus the loop is
closed, and the process continues in perpetuo, "all else
being equal" (which it never is).
But take note of some properties of this simplest of systems.
First of all, the temperature is constantly changing, and thus
"unstable" and in "disequilibrium." We will call this "first-order
instability." But the pattern and the outer limits of that change is
constant ("all else equal"), providing what we shall call
"second-order stability and equilibrium." However, "all else" is
not equal, for the temperature outside the house fluctuates,
so that when that temperature rises, the furnace-on phase is
proportionately lower until, past a certain point, the system shuts
down.
But although the furnace-thermostat system undergoes constant
"first-order" change, no one would deny that it constitutes a
"system." A thermostat alone can not heat the house, and a furnace
alone will not provide a regulated temperature. Together, these
components accomplish what each can not do alone.
Consider next a biotic analog to the thermostat-furnace system,
namely the Canadian lynx-hare cycle, familiar to most beginning
students of animal ecology. When the lynx population is low, the hare
population soars, increasing the food supply for the lynx, causing an
increase in the lynx population, causing a crash in the hare
population, followed by a crash in the lynx population, once again
opening an opportunity for the hares to do their rodent-thing --
da capo, perpetuo moto. So much for the theory. In fact, a
two-hundred year record from the Hudson Bay company confirms the
theory.(17)
Thus we are led to ask: if the thermostat-furnace interaction
constitutes a "system," then why not the lynx-hare interaction? What
do the lynxes and hares accomplish together that they might not
accomplish alone? First of all, they have (at least in part) selected
each other's genomes. Also, the "system" succeeds precisely because
the lynx do not succeed in hunting down the last hare, for
if they did, the ecosystem would collapse. Thus the hares "cooperate"
by obligingly avoiding complete annihilation. More to the point, the
ecosystem to which these two species belong -- comprising climate,
soils, and many additional species, including those that feed the
hares -- provides a "home" for all these species, which could not
survive outside of such a system.(18)
In short, ecosystems are systems because the components
are dynamically interactive. An organism receives its nutrients from
other components, and in turn yields its nutrients to still others. A
functional change in one component organism thus reverberates
throughout the system. The literature of ecology is rich, even
notorious, with examples of inscrutably complex interactions and
"webs" in life communities, catastrophically disrupted by the
introduction of exotic invaders -- notably, the arrival of avian
malaria to Hawaii, of rabbits to Australia, Zebra Mussels to the
Great Lakes, feral goats on the Channel Islands off California, DDT
broadcast to control "insect pests," and so on.
None of this impresses Sagoff, as he scoffs at the idea of
"keystone species," the removal of which can cause the collapse of an
ecosystem. [928-9] He should explain that insignificance to
the orchard growers of California, who now must hire bee keepers to
bring in the little critters to do the work that nature provided for
free, before industrial agriculture "improved" on nature by
broadcasting pesticides. No bees, no pollination; no pollination, no
crop. Who would have thought?!
But don't the California orchard growers just prove Sagoff's
point; namely, that there is 'no prima facie reason to believe that
changes we humans inflict on nature ... must go badly for us?"
[931] After all, they were capable of solving their problem
by importing pollinators. Generally speaking, if, as Sagoff has
argued, "ecological systems and communities are just random,
accidental, contingent , and purposeless collections of biological
flotsam and jetsam, then there is no general instrumental reason to
preserve them." [931n]
On the contrary, it seems that Sagoff's allegedly random, chaotic
hodgepodge of life forms cannot be duplicated by any available amount
of human ingenuity. This fact was vividly demonstrated by that
spectacularly failed experiment, "Biosphere 2." This
two-hundred million dollar project attempted to establish a totally
isolated and enclosed ecosystem which, like natural systems, could
sustain the eight "ecospherians" indefinitely. Instead, reports Paul
Ehrlich and associates,
... the experiment ended early in failure: atmospheric
oxygen concentration had dropped [from 20] to 14 percent
(a level typical of elevations of 17,500 feet); carbon dioxide
spiked erratically; nitrous-oxide concentrations rose to levels
that can impair brain functions; nineteen of twenty-five
vertebrate species went extinct; all pollinators went extinct
thereby dooming to eventual extinction most of the plant species;
aggressive vines and algal mats overgrew other vegetation and
polluted the water, crazy ants, cockroaches and katydids ran
rampant. Not even heroic efforts on the part of the system's
desperate inhabitants could suffice to make the system
viable.(19)
"Biosphere 2," it seems, reiterates J. B. S. Haldane's reflection
that nature is more strange than we know or can even
imagine.(20)
More to the point, it seems to tell us, contra Sagoff, that
not just any collection of aggregated life forms is sustainable --
still worse, we seem quite incapable of assembling any group of
organisms that is sustainable.
Sagoff's charge that the word
"ecosystem" is oxymoronic -- that life communities are random and
chaotic -- places him on a fringe beyond most of the "new
ecologists." Among the biologists leading the charge against "the old
ecology" is Daniel Botkin. Yet Botkin remains an ecologist to the
last for, despite his attacks upon the idols of "equilibrium" and
"the balance of nature," he can not eschew the fundamental concept of
the organized life community -- the ecosystem:
"We are accustomed to
thinking of life as a characteristic of individual organisms.
Individuals are alive, but an individual cannot sustain life. Life
is sustained only be a group of organisms of many species -- not
simply a horde of mob, but a certain kind of system composed of
many individuals of different species -- and their environment,
making together a network of living and nonliving parts that can
maintain the flow of energy and the cycling of chemical elements
that, in turn, support life." (Botkin, DH 7)
4. Ecosystems are sensitive to natural selection among
their components, and thus exhibit the kind of systemic structure,
integrity and resilience that is found among
organisms.
Sagoff contends that while organisms exhibit systemic structure
(logos) and goal-oriented activity (telos), these traits are the
result of evolution. However, he argues, none of this applies to
ecosystems, for "natural selection operates only on creatures that
breed true, that is, creatures that enjoy genetic inheritance.
Ecosystems do not reproduce, possess genomes, or breed true; heredity
is nothing to them. Accordingly, they are not subject to evolution.
We should have to account for any order, design, harmony, or
structure we impute to ecosystems by appealing to some cause other
than evolution." [957]
On the contrary, I will argue, far
from being irrelevant to ecosystems, evolution is the source and
sustenance of these integrated life communities, and thus evolution
suffices to account for any and all "design, harmony, or structure we
impute to ecosystems." This is so, simply because the integration of
the organism with its ecosystem is essential and inalienable, to both
organism and ecosystem. Thus organisms evolve as they do because of
the contingencies in the environment -- which is to say, because of
conditions in the ecosystem of which the organisms are components.
And this is a reciprocal and dynamic interaction: adaptations to the
organism due to the environing ecosystem cause changes in the
ecosystem, which subsequently affect the organism, and so
on.
If this is so, then Sagoff is wrong
to deny an "order of design" in ecosystems while affirming same in
organisms. As Darwin suggests in the case of organisms and species,
ecosystems display an "order of design" grounded in efficient causes.
Since Darwin's time, we have recognized that the eagle's eye, the
bee's dance, and the deer's alertness are all traits "designed"
(better, "selected") to enhance the prospects for survival
of the organisms. Why, then, do such critics as Sagoff have such
difficulty acknowledging that these survival traits "fit," one to
another, into larger patterns of mutually accommodating arrangements?
Any student of biology recognizes such arrangements when they exist
between two species; they are called, symbioses, of which
the cooperative arrangement between the bee and the blossom is the
paradigm example. The bee evolves better to find the blossom, as the
blossom evolves better to attract the bee. Thus emerges a subsystem
of the larger ecosystem. Further investigation reveals that these
interactions are not only binary, but also triadic, quadratic, n-atic
-- i.e., systemic. In other words, the number of species with which
an organism interacts and which determines its genome extends far
beyond those which it eats and by which it is eaten. Just to begin to
extend that list, we must include those that eat and are eaten by
their prey and their predators, and to that the many species which
regulate the soils and climate, and still others that perform
symbiotic services -- and so on, ad infinitum.
And when there is a tear in the
fabric of the system, does not the system react in a manner that is
least traumatic to the component members, for no other reason than
that those members are designed to respond "conservatively," which is
to say, within the capacities of their genomes? There is no
mysterious telic "design" at work here, nor does the ecologist need
to hypothesized such a design.
With evolution brought back into the
ecosystemic picture, the integrated and "self-organizing" structure
of ecosystems ceases to be an unexplained "mystery." For organisms
must have some (albeit not total) order and stability in the
environment if they are to survive in a niche. Natural
selection is simply too slow to allow any macro-organisms to survive
in the sort of chaotic non-system that Sagoff describes. In fact, a
Sagovian chaos describes precisely what is wrong with thoughtless
human intervention into nature; after a clear-cut or the planting of
a monocultural grainfield, there are few niches remaining that can be
occupied by any species, save the managed species (e.g., corn or
red-pine) and, of course, short-lived organisms and rapidly adapting
species such as insect and microbial pests, which must, in turn, be
"managed."
In fact, the "natural" stability of
forest ecosystems precisely explains the threat posed to them by
global warming; for such an event threatens the collapse of
established forests due to their inability to adapt to sudden climate
changes. For example, northern boreal forests are too well adapted to
their "normal climate" to adjust to the change that may be coming,
and, unlike the birds, they can not "migrate" north -- not in the
time scale forecast by the climatologists.
In sum: natural ecosystems are
"self-organizing" simply because the component species require some
order and stability if they are to survive -- that's simple genetics.
And if no ordered stability, then no ecosystem -- or at best, a
simple and desolate system, such as a desert.
Thus far, we have suggested how
ecosystemic evolution reflects and reciprocates the evolution of the
component species. However, there is an even more direct "natural
selection" of ecosystems which takes place even though, as Sagoff
reminds us, ecosystems do not reproduce, lack genomes, and do not
breed true. The basis of this "natural selection" is the simple fact
that most combinations of co-existing life forms are not
sustainable.
Consider the implications of two
laboratory studies. Botkin reports G. F Gause's experiment involving
two protist species, a predator (didinium) and a prey
(paramecium). They did not follow the "Lotka-Volterra model"
of predator-prey oscillation, such as that which took place between
the lynx and the hare. Instead, the predator didinium
devoured the very last paramecium, following which, of
course, the predators starved. A similar, and quite familiar,
experiment involves fruit flies confined to a jar and an abundant
supply of food. The population soars, and then drops to zero as the
flies consume all their food, or alternatively (before the food is
gone), are poisoned by their own waste. (This phenomenon precisely
describes why naturally fermented wine achieves no more than 12
percent alcohol content. At that concentration, the alcohol, a waste
product of the yeast's metabolism, destroys the yeast
cells).
These are two laboratory examples of
failed ecosystems. No doubt there are, in nature, many comparable
failures. In the case of the Canadian lynxes and hares, if the lynxes
had managed to hunt out the very last hare, and no hares were to
migrate in, then that ecosystem would have collapsed. The external
perturbations and internal mutations of which the "new ecologists"
are fond of reminding us, constantly "throw up" new arrangements,
most of which presumably fail. Those that succeed do so (through no
prearranged our "thought-out" design), because they happen to come up
with sustainable patterns of nutrient recycling, energy flow,
population control, and other essential services that characterize a
stable ecosystem. Established ecosystems of which we are aware are
necessarily systems that have thus succeeded. The failed systems,
per hypothesis, are not available for study, unless of course we
happen to find them as they collapse.
This is how "natural selection"
operates "on the ecosystem level." As with evolving organisms,
"ecosystemic evolution" is not planned, but it is selected,
resulting in a systems that are intricately structured, robust,
resilient -- in a word, hospitable to the species that comprise them.
The falsifiable implications of the ecological theory that I have
sketched here are easily articulated and, moreover, are widely
discovered in nature. A catastrophic intervention in the system, such
as a fire or a drought, creates conditions which are no longer viable
for the organisms that are specialized and/or higher in the trophic
pyramid. The system suffers what is called a "crash", leading, not
just to "some other" community, but rather a community that is
simpler (less diverse), less productive (of biomass), and more entropic (ergo more probable). And so we find the desert
which follows the forest and the prairie.
And what if the event impacts just one species? The American
Chestnut blight, or the hunting to near extinction of the southern
Sea Otters comes to mind. If the species is a "keystone" in the
system, and if there is no other species at hand to do the essential
job ("fill the niche"), the system might crash, and be replaced by a
simpler system, which then might evolve in the long-term toward
complexity. This describes the fate of the kelp forests along the
northern California coast, following the loss of the sea otters. If
the system is diverse, however, the lost niche may be occupied by an
adjacent species, as was the case when the oaks replaced the
chestnuts, with little impact upon the stability of the hardwood
ecosystem. (Or so it was in the hardwood forests of New Jersey, where
I grew up. Sagoff describes more severe results elsewhere
[894-5]). However -- and this is the essential point -- that
eastern hardwood forest was essentially unchanged, not because there
was no ecosystem there; not, that is to say, because the "forest" was
nothing but a bunch of trees growing up independently, side-by-side.
The system was able to "repair itself" because of the redundant and
interlocking functions of the component members. It had, so to speak,
the "spare parts" at hand. And thus the catastrophe for the chestnuts
became an opportunity for the oaks.
But now we are back to "the old ecology" -- the notion of an
evolving, self-maintaining system of dynamically interactive
parts.
In short, while it is true that
"ecosystems do not reproduce, possess genomes, or breed true,"
[956] the biotic components of ecosystems do all these
things! And thus, ecosystems evolve as their components evolve.
("Fallacy of Composition," you say? However, not all composition
arguments are fallacies. Ask any chef). Or, putting it another way,
the component species of ecosystems evolve concomitantly, selecting
strategies of survival in their environment. And since that
environment provides both food sources and threats, this means that
those "strategies of survival" must be attuned to the evolving
natures of the other species in the system. The deer owes its
alertness and fleetness to the wolf which selected those traits, as
the wolf owes its keen olfactory sense to the deer which selected
that trait -- and thus they evolve together, two adjoining parts of a
complex system, the parts and interactions of which can never be
fully enumerated, but which include earthworms, dung beetles,
intestinal bacteria, and all the other "little things that run the
world" which, as E. O. Wilson reminds us, we need but do not need
us.
To Sagoff, nature is wonderful enough
without what he considers the ill-founded baggage of ecology. He
writes that: " ... the unlikelihood -- not the perfection -- of the
living world amazes us; the improbability of every plant and animal
leads us to treasure its existence. Species -- even those not yet
named -- command our moral attention because they have emerged
through a billion year old toil of evolution."
[966]
Eloquent and commendable sentiments!
But note what is left out. "Toil of evolution" through
what?! Through the interactive company of other species, of
course, the vast majority of which have passed into extinction. And
these surviving species and their lineal predecessors have prevailed
because, throughout that billion year history, they have functioned
in ecological niches, from which they have secured
nourishment and defense sufficiently adequate to keep this biotic
line intact. Any sudden break in that constant condition, and that
species would not now be available for Sagoff's and our admiration.
Not just any arbitrary and chaotic "hodgepodge" of aggregated
co-existing life forms can accomplish this -- only a moderately
(though not perfectly) stable and integrated "community" of life
forms.
Sagoff's view of nature reminds me of the Bronx Zoo that I visited
as a child. There I encountered, in adjacent and isolated cages and
boxes, one species, and then another, and then another. But as Sagoff
knows full well, along with the rest of us, that's not how nature
"works." What else but a complex "community" of dynamically
interacting life forms, in the context of favorable physical and
chemical conditions, could possibly account for the evolution of that
abundance of life, with all its beauty, mystery and wonder, that
Sagoff treasures, along with the rest of us? Yet, somehow, I find in
his de-ecologized nature much less to wonder at.
5. Sagoff's charge that "nature does not know (has no
logos) and does not care (has no telos) is true -- and irrelevant to
"the moral uses of ecology." Ecological science is not the whole of
an environmental ethic: it is an essential, albeit non-normative
ingredient of such an ethic.
Sagoff's assertion that nature has neither
logos or
telos turns out, in its several expressions, to be
ambiguous.
In one interpretation -- that "nature does not know (has no logos)
and does not care (has no telos)" [923], he is clearly
correct. Knowing and caring are qualities of
sentient, cognitive, and moral beings, which the abstraction "nature"
clearly is not. Trouble is, I cannot identify anyone (apart from
new-age cultists) who believe that nature "knows" or "cares about"
anything. Certainly, no bio-scientists that I am aware of.
Explicating a different interpretation of natural
logos
and telos, Sagoff remarks that certain unidentified
"contemporary theorists ... argue that nature exemplifies a purposive
design -- an equilibrium, homeostasis, or orderly strategy of
development." [940] But are these appositional terms --
"purposive design" on the one hand, and "equilibrium," etc. on the
other -- equivalents? I suggest not. It is quite possible to affirm
"orderly strategy of development," or "equilibrium," and
"homeostasis," and yet deny "a purposive design." The former triad of
terms need not involve ontological or even theological
presuppositions. For while the concept of (first order) "equilibrium"
is fast losing favor among ecologists, such notions of "orderly
development" as speciation and community succession remain
robust.
In fact, ecological theory is not wedded to pre-Darwinian
doctrines such as Aristotelian final causes, "the great chain of
being," and certainly not, as Sagoff suggests, to "creation science."
Nor does ecology assume that ecosystems are somehow "designed" to
benefit humanity. Quite the contrary! With rare exceptions,
scientific ecologists do not attempt "to describe the living
world in ways that answer to religious and moral expectations."
[963]. "Design" and "plan" are Sagoff's words, not the
ecologist's.
Still, the scientist's "nature," though devoid of "knowing,"
"caring," or "purposive design," is not devoid of interest to the
environmental ethicist. The admittedly non-normative laws of nature
(including "laws" of ecology), supply essential consequents of moral
hypothetical imperatives: "if (moral desideratum),
then (obedience to natural law)." In this sense, ecology is
no more or less relevant to morality than physiology is morally
relevant to the doctor, or, for that matter, materials science to the
civil engineer building a bridge. The properties of cyanide are
non-normative. The murderer's knowledge of those properties, and his
willingness to apply that knowledge, constitute his moral guilt.
Those non-normative properties of cyanide, and a knowledge thereof,
are necessary but insufficient grounds of that guilt. Thus we can see
that while medicine is a normative activity, it is based on
non-normative science.
Similarly, the known facts (or laws, if you will) of ecology are
morally significant, albeit non-normative, ingredients of decisions,
say, whether or not to use DDT on crops, to clear-cut rain forests,
to release CFCs into the atmosphere, etc.
6. Traditional ecologists did not (or at least did not
need to) claim that "equilibrium" and "balance" were perfectly
exemplified in nature. Rather, these are "ideal types," of the sort
that are well known in such "hard sciences" as physics.
"Old" ecologists freely use "ideal types" -- arguably, too freely
-- e.g., "equilibrium," "climax ecosystem," "natural balance," etc.,
all of which they acknowledge are not perfectly exemplified in
nature. "Ideal types" are often identified by the following tag, "all
other things being equal" (which, of course, they never are). No one
is particularly troubled when physicists use such "ideal types" as
"perfect vacuum," "absolute zero" or "frictionless machine" -- none
of which are ever found in nature. We should, however, be much more
troubled than we are when we encounter such ideal economic types as
"perfect market" or "economic man." (Cf. our
"Twentieth
Century Alchemy," this site). Most ecological "types," I
suspect, fall in between these extremes.
Why should we be comfortable with the
ideal types of the physicists, but not with those of the economists?
Because in physics, these "ideal types" are derived, "one at a time,"
from carefully conducted experiments and measurements, and they are
asymptotic extrapolations from "near perfect" laboratory conditions
-- "end points" of precisely measured empirical functions. And
finally, in physics, unlike economics, these "ideal types, when
employed in the "hypothetical-deductive" methodology of physical
science, yield falsifiable predictions and thence experimental
verifications.
None of this is true of the
economists' "ideal types." They are not extrapolated to zero, they
are not the single controlled variables of experiments, but rather
are "bundled together" in theoretical constructs. Furthermore, they
"posit" as irrelevant to their theory, conditions which are in fact
inalienable to human motives and economic activity: i.e., they
"factor out" such things as transaction costs, externalities,
collusion, restricted access, imperfect information, distributive
injustice, self-transcending motivation and communal
loyalty. In other words, they fail to describe "real" human
beings and real human communities.
The ecological concepts of "climax,"
"balance," stability," etc. belong, I suspect, somewhere midway in
this scale of theoretical utility between "absolute zero" and
"economic man." Admittedly, many ecologists, and even more,
environmental activists, have given these concepts more conceptual
and theoretical solidity than they deserve and can bear. And we owe
much to biologists such as Botkin, and philosophers such as Sagoff,
for pointing this out to us. But perhaps their criticisms should also
be looked at with caution.
Granted, when it comes to its use of
"ideal type concepts," ecology isn't rocket science. But neither is
it creation science.
7.
Ecosystems
can be recognized to be, in some non-normative sense, "better" or
"worse" than others. ("Healthier," if you prefer). Thus there may
well be good reason to prefer "natural" ecosystems to those
"cultivated" by human societies.
The essential difference, I contend, between (relatively)
"natural" and artificial ecosystems is that undisturbed nature is
"self-managing" -- i.e., absent significant perturbations from the
outside, a mature ecosystem remains pretty much as it is. In
contradistinction, "artificialized" ecosystems (e.g., farms), must be
"managed". And even so, they tend to lose even their
anthropocentrically defined "values," as, for example, topsoil is
lost or soil nutrients of the forest are "exported" along with the
lumber. The new ecologists insist that there are no "constant states"
in natural ecosystems -- that "all is flux." Granted, perfect
constancy is a myth -- an "ideal type," if for no other reason than
no ecosystems are entirely "closed," and thus outside forces
(migrations, climate changes, etc.), keep "bumping" the system.
Moreover, mutations are constantly occurring to organisms within the
system. But here is the essential point: the heraclitean "flux" in
natural ecosystems that so captivates the attention of the new
ecologists is a very slow and a self-healing process, while
anthropogenic effects are sudden and disruptive.
But need we be so suspicious of human
interventions in nature? Might we not, instead, "look to technology"
to overcome biotic limits, just as we have done so to overcome
physical limits, e.g., to transportation. "No one," Sagoff remarks,
"still believes that we should not fly because God did not give us
wings."(21)
Answer: we can fly today, because we have learned the physics of
aerodynamics, not because we have "overcome" physical laws. We can
not overcome biotic constraints, precisely because we do not have an
understanding comparable to our understanding of physics and
mechanics. In the life science, we are not like rocket scientists
aiming for the stars; we are more like Icarus, pasting feathers on
our arms with beeswax.
Furthermore, those limits of natural
law, so rigorously obeyed even by rocket scientists, are, in the case
of ecology the very components of our fundamental
bio-physical-chemical nature, and thus are found to be even more
confining than the constraints of aerodynamics. Here the statement of
the Ecological Society of America, which Sagoff sets up for
criticism, is entirely correct: "nature has a range of ways to be,
but there is a limit to those ways, and therefore, human changes must
be within those limits." [920] What physical scientists or
engineer could disagree with that?
Another difference between natural ecosystems and artificial
"extractive systems" is that the latter require the importation of
labor and nutrients if they are to be sustained, and even so, their
life-cycle is numbered in decades or even years, while natural
systems persist for millennia (though not forever, as Prof. Botkin
reminds us) on nothing more than the importation of solar energy.
I am reminded of a remark I once
heard from a commercial forester: "The northwest forests were very
unhealthy when we found them in the last century." "Thank God," I
replied, "we got there just in time!" The managed "health" of
Weyerhauser's forests is something quite different than the
self-maintaining "health" of the old-growth forest.
The barren hills of Lebanon, where
the cedars once stood; the deserts of Iran, where Darius could once
ride from Persephelus to the sea, in constant shade; the deserts of
north Africa, once the granaries and orchards of the Roman Empire --
all these testify to the ultimate consequences of careless human
intervention with natural systems. And yet, a few summers ago I could
look across a broad Italian valley in constant production since the
days of the Etruscans over three thousand years ago -- three thousand
years of "inefficient," solar-driven, organic agriculture.
Are we now to conclude that there are
no noteworthy differences between the ecosystems of ancient Lebanon,
Persia, and Algeria, and those of today? Clearly they are different
from the point of view of human purposes. Are they now "just another
kind of ecosystem, no better or worse than before?" There are
noteworthy differences; just to begin, diversity of species and
productivity of biomass.
Jonathan Schell describes the post
atomic holocaust earth as "a republic of insects and grasses." No
more forest, no megafauna, no homo sapiens. "But no matter,"
we are told, "it is just one ecosystem following another. Who's to
say that one is better or worse than another? " Such an attitude is
the moral dead-end of the road down which the radical ecological
deconstructionists would lead us.
8.
The ultimate inscrutability of
ecosystems, suggested by the deconstructionists, far from undermining
ecological morality, serves to strengthen it.
How has this criticism of "the old ecology" eroded the scientific
foundations of such ecological moralities as Aldo Leopold's "Land
Ethic?" Arguably, not very much.
We owe a debt to Mark Sagoff, along with Soulé, Botkin,
Shrader-Frechette and other critics of traditional ecology, for
indicating how the "pop ecology" of the activists and the New Agers
has wandered far beyond the characteristic skepticism and
qualifications of the scientists. "Natural communities," the new
ecologists remind us, are far more complex and inscrutable than we
may have imagined. But this is exactly what such eco-moralists as
Aldo Leopold have been saying all along. And if "balance and
equilibrium" turn out to be oversimplifications, "constant gradual
change within limits" is a concept quite congenial with ecological
morality.
If "the new ecology" retains four essential concepts of the old,
then, I think, this will be foundation enough for a sound ecological
morality. These are: (a) that life communities are systems
-- of organisms in dynamic interaction, (b) that ecosystems can be
meaningfully distinguished and graded in terms of biodiversity,
productivity, relative stability and negentropy, (c) that a
differences in the scale of change are significant, and (d)
that the complexity of natural systems is beyond our understanding,
and perhaps even our imagination -- a fact that mandates respect and
caution as we intervene in nature.
As for "ecological science" itself, I believe that we can rescue
it from the unwarranted fellowship of "creation science." For, as we
have seen at the outset of this paper, ecology utilizes productive
and discriminable concepts, and it does provide falsifiable
hypotheses and predictions, although, as numerous critics have
correctly pointed out, there is vast room for improvement in this
regard.
Sagoff demurs, as he dismisses ecology with the suggestion that
"the only non-theological tenable position" is "that nature is just a
pointless hodgepodge of constantly changing associations of organisms
and environments." [901]
I submit that the answer to this charge is quite simple and
straightforward. We need only ask:
-
Does the study of ecology have anything to tell us about
resource or population policies? Or, for that matter, such applied
biological sciences as forestry, fisheries, agriculture?
-
Would anyone, having learned the allegedly "vacuous" theories
and concepts of ecology, look at the world more "realistically"
than, say, an adherent of "creation science?"
If the theories and concepts of ecology constitute authentic
knowledge, then the application of such knowledge should have
predictable and discriminable consequences -- it should, so to speak,
"make a difference." I submit that it has: in agriculture, forestry,
and Leopold's field of wildlife management.
Because significant and enduring patterns do exist among that
seeming "hodge-podge of constantly changing associations," we should
continue our inquiries in ecological science. And we would be
well-advised to pay attention to the traditional ecologists, while
keeping a critical eye on their rhetorical excesses.
I doubt that such "new ecologists" as Soulé and Botkin
would disagree.
9 Because virtually all "deconstructionist ecologists"
accept the theory of evolution, they must presuppose some degree of
design, order, constancy and resilience -- i.e., some system in
ecosystems.
Our final defense of the ecosystem concept follows from much of
our preceding argument, and will serve to recapitulate and summarize
much that has gone before. Here we will utilize a method employed by
a philosopher much-admired by both Mark Sagoff and myself: Immanuel
Kant.(22) We then ask: "If we assume
(as all parties to this dispute assume) that species evolve through
natural selection, what then must we presuppose for evolution to be
possible at all?" Quite simply, I would suggest that the clear answer
is "a moderately integrated, stable and persistent ecosystem." In
particular:
-
first of all, if species evolve,
they must evolve by adapting to their environments.
-
because such adaptation involves the availability of food and
adequate modes of defense, this environment is necessarily a
biotic environment -- i.e., species evolve in the company
of other species.
-
The more complex the system, the greater number of intervening
variables (e.g., trophic pyramids) between the organism and the
abiotic environment.
-
species that persisted for a long period of time did so
because they (a) survived and (b) adapted to changing conditions
(i.e., they evolved).
-
they (a) survived because the physical and biotic
environments were not in a state of constant, chaotic and extreme
change.
-
They (b) evolved, because this environment was not
totally static.
Thus, it would seem that in their moderate formulations, both the
old and the new ecologies are correct: The former (a) points out that
species survive due to stability in the environment, and the latter
(b) correctly reminds us that species evolve due to changes in the
environment, including, of course, changes brought about by the
evolution of the component species. The crucial issue is that of
rate and scale of change. On the opposite ends of
this continuum (outside the scope of scrupulous science, I would
suggest) are those, on the one hand, who celebrate "perfect" balance
and equilibrium, and on the other, those who claim to find no
"system," much less "integrity," in ecosystems.
TOWARD A
"RECONSTRUCTION" OF ECOLOGY
This essay has been a clash of
adversaries: we have countered Sagoff's adversarial critique of
"theoretical" (or "old") ecology, with a rebuttal critique of
Sagoff's position. However, we should close on a positive note, with
acknowledgment that our worthy adversary's critique has some points
of merit, that ecologists, old and new, would be wise to consider.
Among them:
-
some ecological language is unacceptably vague and ambiguous.
In particular, (a) the "baseline problem" ("what is a normal
ecosystem?") and (b) the "boundary problem" ("when in time, and
where in space, do ecosystems begin and end?") are both in urgent
need of attention.
-
the ecologist's classification scheme must be refined and
expanded. An ecological Linnaeus or Mendeleev is overdue.
-
ecologists must be more mindful of the falsification
rule. They must be prepared to describe ecological systems,
functions and components in a manner that clearly excludes
discriminable alternative conditions in nature. While much of
ecological theory fulfills this falsification requirement, some
does so only marginally, and some not at all.
-
ecological scientists must be careful not to allow their
ideological and political agendas, and their moral enthusiasms to
"captivate" their scientific claims.
That said, we reiterate, in closing, our conviction that life
forms survive and flourish, as they must, as participants in
organized, integrated and dynamically interactive systems --
ecosystems. As components of these "systems," the life forms
accomplish in concert what they could not accomplish separately. All
this, I submit, has been made abundantly and irrefutably clear by
innumerable scientific studies of energy flows, nutrient recycling,
information interchange, and symbiosis.
Somewhat less certain is the existence of significant degrees of
stability, equilibrium and resilience in
ecosystems. (I say "significant degrees," since no scientist claims
that these "ideal types" are perfectly exemplified in nature). Least
of all are ecologists able to explain how these alleged properties
are manifest in ecosystems.
Sagoff suggests that the failure of biologists to
explain
"intelligible or purposive structure or direction [and]
self-organizing capability" in ecosystems [958], constitutes
sufficient reason to doubt that such qualities exist in
ecosystems.
Granted, the failure to explain an X might at times be
grounds to doubt its existence. Thus a suspect's inability to
"explain" his whereabouts at the time of the crime casts doubt on his
claim of innocence. On the other hand, if the simple fact of
X's existence is compelling obvious or supported by an
abundance of evidence, a lack of "explanation" might in no way
mitigate our awareness of that fact. The detective, upon first
encountering a corpse, has no explanation as to how the victim died.
This in no way diminishes his awareness that he is in the presence of
a dead body. Victims of the Black Plague, utterly ignorant of any
explanation thereof, were fully aware that they were deathly ill. And
finally, Charles Darwin's utter failure to "explain" variation within
the species did not compromise the strength of his theory. The
documented fact of such variation quite sufficed.
Whether or not biological science has come up with a robust
explanation of the putative "self-organizing" structure of
ecosystems, I will leave to the ecologists to judge. However, the
fact that ecosystems often contain web-like interactions is
evident by numerous well-known case histories: the extinction of
indigenous Hawaiian birds following the introduction of avian malaria
from European ships; the devastation of the Australian outback
resulting from the release of rabbits; the collapse of the Kaibab
forest ecosystem following the extirpation of the top predators; and,
of course, the reproductive failure of hawks and eagles due to the
bio-multiplication of DDT and its decay products. And the fact of the systemic nature of life communities has been
rendered beyond dispute by the aforementioned studies of energy and
nutrient flow, information exchange and symbiosis.
These cases and investigations all
testify to the fact of species interdependence in
ecosystems, whatever may be the cogency of scientific explanations
thereof.
The lack of a clear explanation of
the functioning and properties ecological systems does not constitute
a refutation of ecological theories and concepts and theories.
Rather, it presents an urgent and daunting challenge to ecological
scientists, now at work and still to come.
In the meantime, we remain well-advised to tread carefully upon
the Earth, upon which we are recent newcomers.
Copyright, 1997, by Ernest Partridge
NOTES
1. Aldo Leopold,
A Sand County Almanac, New York: Oxford University Press,
1989, pp. 224-5.
2. Michael Soulé, "The Social Siege of
Nature, Reinventing Nature?, ed. Michael E. Soulé and
Gary Lease, Washington, DC: Island Press, 1995, p. 143.
3. Mark Sagoff, "Muddle or Muddle Through?
Takings Jurisprudence Meets the Endangered Species Act," The
College of William and Mary Law Review, 38:3, March, 1997, pp.
825-993. Sagoff's critique of theoretical ecology is found primarily
in Sections IV and V (pp 877-968). Because of the large number of
citations from this work, subsequent references thereto will be found
in brackets in the text.
4. I must note that my personal and
professional debt to Mark Sagoff is beyond measure. His critique of
the economization of public environmental policy is brilliant and
devastating, and I have utilized his work in my classes and writing
to great effect. I am so much impressed and convinced by his work in
this field, that I have been much concerned that I might become a
Sagovian disciple -- and discipleship is most unbecoming a
philosopher. After reading his work on ecology, however, this concern
about impending disciplehood has been considerably diminished.
6. Daniel Botkin,
Discordant
Harmonies, New York: Oxford University Press, 1990, p. 62.
7. loc. cit.
8. Mark Woods expresses this view (of which he
is critical) with admirable clarity: "We cannot identify what can
harm wilderness because there is no such thing as a static, baseline
wilderness against which harm can be measured, and we cannot identify
what can disturb wilderness because everything can. Further, it may
be impossible to characterize what wilderness is (as it now exists)
because wilderness is in perpetual change." Mark Woods, "Upsetting
the Balance of Nature: Can Wilderness Preservation Survive the New
Ecology?," A paper presented at a meeting of the International
Society for Environmental Ethics (Pacific Division, American
Philosophical Association), March, 1998, Los Angeles, CA.
9. "If ecosystems are unstructured, transitory,
and accidental in nature, it would seem to follow that no general
economic or utilitarian grounds exist for protecting them from
change." And, "If ecological systems and communities are just random,
accidental, contingent, and purposeless collections of biological
flotsam and jetsam, then there is no general instrumental reason to
preserve them." Sagoff, op. cit., 931-2, 931n.
10. Regarding the biodiversity crisis, Sagoff
parts company with most of the "new ecologists," who are as alarmed
and appalled as most biologists at the current "extinction
spasm."
11. Once again, I would separate this position
from that of most of the "new ecologists." From 1980 to 1982, I was a
visiting professor of Environmental Studies at the University of
California, Santa Barbara. At that time, the chairman of the program
was Daniel Botkin. I vividly recall how, at that time, he supported
the "habitat strategy" of preserving the California Condor -- in
other words, the "ecosystemic approach." As we shall discover later
in this paper, Botkin, while notoriously opposed "equilibrium" and
"stability" models of ecology, nonetheless asserts that ecosystems
are in fact systems. (Botkin, op. cit., 7).
12.I have lost the source of this marvelous
put-down, though I believe it first appeared in a scholarly review in
the last century. Much too witty to be so confined, it has long since
entered into general conversation and discourse.
13. Botkin, loc. cit.
14. Botkin,
op. cit., 58-9.
15. Mark Woods concurs: "... no ecologist has
held the view that nature is static and completely unchanging.
Rather, as proponents of [the new ecology, such as Botkin and
Budiansky] would have us believe, when ecologists have spoken of
'stability' in nature usually they have meant that all the variables
of any population, community, ecosystem, etc. will return to
equilibrium conditions after they have been displaced or disturbed.
In other words, in spite of disturbances (variables) in nature, the
structures and compositions of nature remain or return to the
same.
"Has anyone really held this view? In his equilibrium
theory of succession leading to climax communities, Clements
(organismic model) stressed that such an equilibrium was a dynamic equilibrium: 'Even the most stable association is
never in complete equilibrium, nor is it free from disturbed areas
in which secondary succession is evident.' Elton (community model)
claimed: 'The 'balance of nature' does not exist and perhaps never
has existed.'" Woods, op. cit., pp 22-3.
16. For an excellent treatment of "the scale
issue," see J. Baird Callicott, "Do Deconstructive Ecology and
Sociobiology Undermine Leopold's Land Ethic?," Environmental
Ethics, 18:4, (Winter, 1996), pp. 369-372 (the final two
sections of the paper).
17. Allee, Emerson, Park, Park and Schmidt,
Principles of Animal Ecology, Philadelphia: Saunders, 1949. Cited by
Botkin, op. cit., 46.
18. Predictably, Daniel Botkin (from whose
book I have borrowed these citations), sees things differently. He
points out that the "Lotka-Volterra equations" that describe a
perfectly "symmetric, out-of-phase oscillation between predator and
prey," do not exactly describe the empirical data brought back from
the field. "Predators," he concludes, "do not seem to control the
abundance of their prey in an exact sense." The operative word here
is "exact." But for such "exact control" to be operative -- i.e., for
there to be a "perfect" and constant "balance" of nature -- all other
factors (e.g., climate, migrations, etc.) would have to be constant
and mutations would have to cease. And no biologist has ever defended
this such a concept of "stability" and "equilibrium. All agree that
"all else" is not "equal." Botkin denies "stability" in the
"first order sense," as he rhetorically asks: if "a pilot guaranteed
that an airplane was stable and very constant in flight, but its path
through the air graced out the curve of the lynx's population... Who
would want to call that airplane stable?" But that analogy is faulty,
for it is the "second order stability" that interests the ecologists.
And the data on lynx population that Botkin supplies displays a
sustainable pattern of fluctuations -- a "second order stability."
(Botkin, op.cit., 38, 47, 48).
19. Paul Ehrlich, Gretchen Daily, Scott Daily,
Norman Myers, James Salzman, "No Middle Way on the Environment," Atlantic Monthly,
December, 1997, p. 101.
20. The exact quotation: "Now my own suspicion
is that the Universe is not only queerer than we suppose, but queerer
than we can suppose." Possible Worlds, title essay
(1927).
21.
Mark Sagoff,
"Ecosystem Science and Environmental Law," p. 4. This is the
unpublished manuscript distributed to the Integrity Group at its
meeting in Montreal, October 17-20, 1995. It was later revised and
incorporated into the College of William and Mary Law Review paper,
"Muddling and Muddling Through....," loc. cit.
22. Kant asked,
"what categories of understanding must exist for empirical knowledge
to be possible at all?" And in the realm of ethics, he asked, "what
human capacities must be presupposed for morality to be possible?" Thus the similarity with our question, "what must be assumed for
evolution to be possible?" But the Kantian model has disanalogies as
well. Kant was searching for "synthetic a priori" judgments
-- judgments that are neither "true by definition" nor gained from
experience, but rather are the preconditions for empirical knowledge.
I claim no such status for the "presuppositions of evolution" that I
sketch above. Rather, these proposed assumptions should all be open
to scientific investigation.
