Nature's Holism (condensed - 3)
Nature's Holism (condensed - 3) <<<][Next -4
Coevolution and Environmental Management

(This chapter is not in the book "Nature's Holism".)
Introduction:
Environmental management is at the top of many government's agenda today. Key phrases are bandied about, terminology that points to what is needed, without necessarily offering a solution. Key terms in the topic of environmental management are, sustainable future, environment, life support systems, population, resource, pollution, environmental protection, ecology, soil erosion, climate change, human civilisation, culture, society, sustainable solutions, coexist in harmony, human needs and ecological needs. It is around such ideas that environmental science is developed.

Technological optimists (such as myself) believe that advancing technology will play a big role in solving the current trend of environmental degradation. The aim and policy of such technological advances should be to lessen our impact upon, and damage to the environment. Many different groups and organisations have adopted policies and actions to counter this decline. The momentum of our surging populations is so great that these efforts are having little long-term benefit.

This document explores an ecological solution to an ecological problem. Here, I take the coevolutionary aspect of nature, as epitomised by the bee and the flower, and investigate how principles derived from this idea can be applied to solve some of our environmental problems. This approach makes some important assumptions: evolution has occurred and continues today, evolution takes place within an ecological context and humans are an evolving species. Coevolution is reciprocal evolution of two or more interacting species. This requires the long association and evolution of interacting species. The bee and the flower are two highly coevolved species showing a high degree of interdependence. Reciprocal selective forces result in the evolution of one species affecting the selective forces upon the other species. Evolution is the physical and genetic change with time of living creatures, caused by the process of natural selection. Natural selection is the mechanism of evolution proposed by Charles Darwin. Natural selection is the evolutionary process of differential survival and reproduction of organisms because of their differing genetic constitutions being subject to environmental forces. It leads to adaptive evolutionary change. As the offspring from parents show variation (physical, physiological and behavioural) with a genetic basis, there may be differential survival at each generation. Environmental factors will "select" for features that suit the prevailing conditions in a process defined as natural selection. For example, an animal may survive a drought because of a better kidney function. This may enable the animal to survive and reproduce in a period of drought when many other individuals die. If this characteristic is genetically based, survival and reproduction will enable the transmission of this trait.

A Coevolutionary Approach:
Within the context of evolution and ecology are two inter linked ecological processes: perpetuity and compatibility. Nature shows an interdependence, expressed as a reciprocity between long-associated organisms (living plants and animals), forming a natural panoply. Creatures in nature have the instinct to perpetuate. Perpetuity is the continual and natural drive or impulse for survival and the perpetuation of the individual and its offspring. Survival and perpetuity reflect an aspect of natural selection, which is the consequence of good design. Evolutionary processes (time) lead to interactions and behaviour that provide a degree of compatibility (interdependence) between long-associated organisms. A compatible animal exhibits behaviour reducing its effect upon the living component of the habitat upon which it depends for survival. If measured as a relative value, increased efficiency would be found. Recorded examples are as numerous and diverse as nature herself (see Naure's Holism)!

Atoms do not change their nature in any fundamental or evolutionary sense in the formation of molecules. Subatomic structure does not conform to the "whole". From the molecule upwards, coevolution is possible, conforming that level to the whole. All evolutionary changes are essentially molecular (Behe, 1998). Atoms provide constraints to what molecular forms are possible.

At the ecosystem level of organisation, with interdependence and coadaptation found between associated organisms, the mode of perpetuation is to be found in the parts, the individual organisms. Associations evolve so that the animal is "suited" to use the resources of its niche. In an experiment called Prisoner's Dilemma (Axelrod) that tested interactive models, the interactive process, where elimination was possible, did not lead to survival of the fittest as is generally understood of evolution today, but led to the fittest being those that COOPERATED. Cooperation implies INTERDEPENDENCE. Biotic interactions during the evolutionary process lead to interdependence of associated organisms. A species' formation of territories, instead of being a purely competitive mechanism, is behaviour through which beneficial cooperative behaviour can be expressed. The evolution of cooperation requires that successful strategies perpetuate and that there is a source of variation in the strategies employed. Darwinian natural selection requires the same conditions, with variations provided by genetic mutations.

Much of what Darwin said has holistic flair. He uses his term "struggle for existence" in a "metaphorical sense" "INCLUDING DEPENDENCE OF ONE BEING ON ANOTHER (equated partially with compatibility), and including not only the life of the individual, but success in leaving progeny" (equated with perpetuity). We find a more subtle understanding of competition as an interaction in his statement that: "It is good thus to try in our imagination to give any form some advantage over another. Probably in no single instance should we know what to do, so as to succeed. It will convince us of our ignorance on the MUTUAL RELATIONS OF ALL ORGANIC BEINGS; A CONVICTION AS NECESSARY, AS IT SEEMS TO BE DIFFICULT TO ACQUIRE." This mutuality leads to compatibility, so Darwin says, "Let it be borne in mind how infinitely complex and close fitting are the MUTUAL RELATIONS of all organic beings TO EACH OTHER and TO THEIR PHYSICAL CONDITIONS of life." "Thus I can understand how a flower and a bee might become slowly, either simultaneously or one after the other, modified and ADAPTED in the most perfect manner TO each other, by the continued preservation of individuals presenting MUTUAL and SLIGHTLY FAVOURABLE DEVIATIONS OF STRUCTURE." Further, "if any one species does not become modified and improved in a corresponding degree with its competitors, it will soon be exterminated."

Darwin emphasises the associations of nature by first noting that "Competition should be most severe between allied forms, which fill nearly the same place in the economy of nature. Its "COROLLARY OF THE HIGHEST IMPORTANCE: That the structure of every organic being (organism) is related, in the most essential yet often hidden manner, to that of all other organic beings, with which it comes into competition."

An established scientific model, the Lotka Volterra model aids in looking at coevolutionary factors, or rather the factors that bring about coevolution.

dN1 (K1-{N1+i12N2})
----- = r1N1 ---------------------
dt K1

The left side of this equation says, "the rate of change of a population's numbers (N) over time (t) equals (=). On the left, the factors involved in population growth are the rate of population growth (r), the current population numbers (N1), the carrying capacity of the environment (K1), the numbers of another species (N2) utilising the same resources and the degree to which the second species affects the first species (i12). Traditionally, this equation models competition (Smith, 1990), while here interactions of any form between associated species are considered. Putman (1994) recognises this possibility. After Gause, competition dominated the perception of ecologists dealing with the Lotka-Volterra model and ecosystems.

Scientisits have modified the Lotka-Volterra model to explain other forms of interaction such as mutualism. Biological mutualism is a beneficial, reciprocal relationship between two species. The interaction favours survival, growth or fitness of both species (Smith, 1990). To model this, "The general approach has been a modification of the terms of the Lotka-Volterra equations for competition in which the negative alphas of competition become positive." They term this positive coefficient the coefficient of mutualism. By the time Putman published his book, "Community Ecology" in 1994, this positiveness, negativeness or neutralness of biotic relationships was established : "Indeed all the various relationships through which the various members of a community might interact, may be represented as ++ (mutually beneficial); +0 (beneficial to one participant, not affecting the other); and +- (beneficial to one, damaging to the other)." To this he adds two more in a table, -- (for competition) and 0- (for incidental damage).

The most important variable in this model is the competition coefficient, alpha (i12), which I have call the interactive coefficient (i-factor) to accord with the compatibility idea and allow the consideration of all interactions, including competition and cooperation. Interactions between individuals of the same species are termed "intraspecific", while those between individuals of different species are termed "interspecific". The competition coefficient (alpha) represents the strength of interaction (i-factor), showing the extent to which the growth rate of species 1 influences that of associated species 2 (Putman, 1994). i12 is the interactive effect on species 1 of species 2 (the effect of species 2 on species 1). INTRASPECIFIC interactive effects represented by the i-factor, or the "cost" of the interactive effect of two individuals of the same species, are given a value of 1. All other interactions with other species are measured RELATIVE to this value. In other words, we allocate the average interactive effect of two individuals of the same species a "cost" of 1. There are many ways of expressing this. Colinvaux (1973) explains that "if an individual species 1 treats an individual of species 2 as one of its own kind, i21 = K2/K1 = 1." It is essential to realise that in this model, whenever you are dealing with the above formula for species 1, you also have to consider the reciprocal formula for species 2. By doing this you arrive at the coevolutionary mechanism.

In the standard analysis of the Lotka-Volterra Model, ecologists recognise the possibility of coexistence through decreased interactive effects between species (Smith, 1990). When intraspecific competition inhibits the growth of a population more than interspecific interactions do, coexistence is possible. Smith (1990) notes that coexistence occurs when "Each species inhibits its own growth through density-dependent mechanisms more than it inhibits the growth of the other species." Colinvaux (1973) also notes that "for weakly competing populations, then, the Lotka-Volterra equations predict that both should persist indefinitely, their populations fluctuating only gently about equilibrium levels." Unfortunately, Smith and other ecologists did not realise the evolutionary implications of this "WINDOW OF OPPORTUNITY" that opens between two interactors under such conditions.

Adaptation, when between organisms that are both evolving, leads to what appears like group selection, but is coadaptation. The conclusion drawn from the model is that behaviour or physical changes that reduce the interactive effect or "cost of interactions" between individual organisms of the same (intraspecific) or different (interspecific) species, is selected for through natural selection, as such behaviour leads to ecological stability and individual fitness. It is this two pronged benefit that is so important and is seen so clearly in the bee and the flower. Natural selection decreases the intensity of interaction between two associated species through their diversification as this is an economic advantage. Specialization and diversification are adaptive advantages, improving survival potential. Strategies of diversification are numerous and often very subtle.

Chaos:
The limits imposed by the environment, reflected as the environmental carrying capacity (K), plays a role in natural selection and coevolution. To understand more how this works, we need to look into the fairly new science of chaos. It is important to be aware of inherent limitations within ecosystems. Animals have an inherent maximum reproductive rate, providing a physical constraint. A human mother cannot have twenty offspring in one year. Consequently, population growth rates are a function of existing population numbers. This year's population determines the limits to growth of the following year's population. Biological and physical processes are bound by real and natural constraints on possible behaviour. If the system under study is in some way a whole or a closed system, these constraints will limit the dynamic processes that are possible.

Models are always mere approximations of the real world. They have severe limitations. Regular and simple equations can produce irregular behaviour, pointing to both the limitations in such (mathematical) models and the potential for very complex behaviour in nature's intricate web of interactions. Population growth has limits that are inherent within the animal. Over time feedback occurs. This year's population will have a bearing on the size of the following year's population. Mathematics is used to explore the effects of natural processes in an attempt to make predictions such as the dynamics of fish populations for commercial fisheries, the expected course of disease epidemics passing through a population and so forth.

The formula: x(next) = rx(1-x)

represents a mathematical formula supposed to model nature. r represents the population growth rate, x is population numbers.

Let us use the model's expression to see what occurs in nature and see how chaos can occur. In an expanding population there is a slow incremental increase in the growth rate (r) of the population over time.Usually, there is an initial, rapid increase in population numbers where resources or the carrying capacity of the habitat do not limit the growth rate. Growth is limited by the intrinsic rate of increase of the population. The organism has biological limits to the number of offspring that it can produce. Next, the curve flattens as the effect of environmental limits comes into effect. Feedback from the limits that define the carrying capacity of the environment cause this. If the growth rate does not respond sufficiently to the responses from the environment, the animal's numbers explode into chaos near the carrying capacity of the environment. At one point extinction occurs. When the growth rate is very high, this happens very quickly. Growth is smooth until the carrying capacity is approached and then with sustained growth, suddenly the smooth curve bursts into chaos, with population numbers fluctuating wildly. This is the region that chaos theorists call the edge of chaos. (This process is illustrated graphically and in detail at http://www.ecotao.com/holism/chaosintro.htm ). Under nomal conditions, the growth rate (r) decreases near the carrying capacity. Clearly, the reproductive rate is subject to environmental constraints. Plant grazers, for example, would find less food available as their population numbers in an area increased over time. Thus as population numbers (x) approaches one, the reproductive rate (r) must decline. The animal causes changes to its environment and then responds to its environment (feedback). This environmental change takes on many forms, from available nesting sites to sufficient food for the population, to environmental pollution as we humans are discovering. By inserting this condition into our formula, we find that the population growth never explodes into chaos. Here there is a rapid feedback from environmental conditions affecting population growth rates. This is more likely the common case in nature. Natural selection has also selected for behavioural responses in some species, so that their behaviour reduces their reproductive rate before the population is decimated by resource limits.

A situation can occur in nature, where some resource suddenly disappears and a population's growth rate (r) or population density is suddenly too high. This can happen during periods of drought. It can occur in the oceans to important fisheries when temperature changes (e.g. El Nino) alter the availability of food resources or when commercial trawling reduces the food available to wild animals. Sometimes, birds, seals or other predators of fish stocks starve to death in large numbers. This happened to the seal population off the west coast of Southern Africa in 1994. In effect, a resource limit (environment), throws the population into chaos. This immediately influences the original growth rate, decreasing it. Chaos smooths out to a new stable situation. Note that there is no self-regulation here, only the dynamics of living, responsive and dynamic systems!

Environmental management:
When this principle is applied to environmental management, we see that our attention and emphasis should be on ways of reducing our interactive effect upon nature, species and ecosystems. In our cultural evolution, we have passed through three economic strategies: hunter gatherer, agricultural society and industrial society. The fouth stage we are entering is to become an ecological society. As hunter gatherers, we had little impact upon nature, because our population numbers were low, we did not control our environment by converting whole ecosystems and we moved across all niches and ecosytems, adapting to new food resources as conditions changed. Agricultural societies cause more harm to the environment than hunter gatherers, but the most damaging is the industrial society that evolved and prevails today. Industrial technology emerged with the steam engine, factories and mass production, only 200 years ago.

Paul and Anne Erlich proposed a formula to model the human impact on the environment. They made various assumptions:

[i] We need to halve our impact (I) upon the environment, as the impact is already unsustainable. The earth cannot sustain the
projected growth in the world's population, nor our current patterns and levels of consumption (Kennedy, 1993).

[ii] Populations (P) will double to 10 billion by the year 2050 (a projection of current growth trends).

[iii] Current development trends mean that the average consumption (C) per person will quadruple by 2050, largely through
increased affluence of developing countries such as China and India.

[iv] To handle these changes will require technology (T) to adjust the "environmental intensity of consumption" (Ekins, 1993).

This formula then becomes:

I = PCT.

Where the subscript 2 is the future condition and 1 is the present,

I2 = 1/2 I1

P2 = 2P1

C2 = 4C1

and I2 = 2P1 *4C1 *1/16T1.

In other words technological innovation must reduce our technological intensity (T) to 1/16 of its present level by the year 2050 to effectively counter the current growth trends. Clearly, we cannot return to hunter gatherer type lifestyles, so a control of population growth is the main tool at our disposal. We will, by necessity, depend heavily upon technology and innovations to create a more benign existence of humanity with nature.

Reducing consumption can also be very effective. To do so would require some major changes in our lifestyles. An average American eats 68 kilograms of grain per person annually, while 680 kilograms of grain per person is fed to U.S. livestock each year! In developing countries the total grain consumption averages 180 kilograms per person per year, mostly eaten directly.

Currently, there is not too much that we can do about population growth. We need to assume that predicted numbers will be attained, these ranging from the 10 billion by the year 2050 to an estimate of 9.5 billion by the year 2100 (Eldredge, 1999). The additional three to four billion people may also try and attain a better standard of living that their parents. Paul and Anne Erlich, in presenting the above formula, assumed that consumption, due to greater general affluence, would quadruple. This placed a very heavy demand upon technology to effectively counter the current growth trends by the year 2050 so as to reduce our technological intensity to 1/16 of its present level. However, we need to take a closer look at the average consumption per person.

Firstly, we now possess the technology to invent materials that can either be recycled, or are not polluting. Glass, essentially sand, in various forms, could replace many of today's materials. Foamed glass could even replace the concrete of modern buildings (Amato, 1999). Recycling and the use of non-polluting raw materials and products therefore becomes an essential social and governmental strategy.

Secondly, and just as importantly, a great reduction in our impact upon the environment can be achieved through the adoption of a more vegetarian diet. It is quite feasible for the average westerner to reduce meat consumption to 1/10 of the current level. Ayres (1999) noted that the per capita consumption of meat doubled between 1950 and 2000. Ayres estimated that 7kg of feed grain are required to produce 1 kg of feedlot beef. The biological conversion efficiency is generally quoted at 10%, so a ratio of 7:1 is good. By reducing meat consumption to 1/10 of the current level, we effectively free about 6kg of grain per kilo consumed. The rate of consumption of this meat, being a tenth of the previous level, also has other benefits over and above gross consumption. Improved health and lowered medical costs is one. Simply, the demand upon the environment from this component of the human impact upon nature, can be reduced. If the population does double, while we do manage to reduce meat consumption to 10% of the current level, the impact of this component need only be about 20% of the current level by 2100.

Ayres included fish in his reckoning of costs of "hugely inefficient use of freshwater and land, heavy pollution from livestock feces, rising rates of heart disease and other degenerative illnesses, and spreading destruction of the forests on which much of our planet's life depends." However, fish fit only a few of these categories. If we were to eat the fish currently trawled and made into fish meal, we would immediately increase the effective availability of this highly nutritive protein and fatty acid source bay a factor of 10, simply by not converting it into beef of some other flesh first!

Note that the "environmental intensity of consumption" (T) is not equivalent to the energy consumption of an individual.
Energy consumption can be high while T is still low. This would require that energy consumption be environmentally benign. T is equivalent to the interactive factor (i-factor), discussed in the section on the Lotka Volterra model. The basic conclusion here is the same as deduced from the model. We need to reduce T, or the interactive effects upon the environment. Our impact upon the environment has to be drastically reduced if we wish to maintain the present quality of life of the West. This is the essence of compatibility and its expression can take many forms.

To achieve this compatibility with nature, we need a new view of nature, as described by the Brundtland Commission: "We have the power to reconcile human affairs with natural laws. And to thrive in the process. In this, our cultural and spiritual heritage can reinforce our economic interests and survival imperatives" (Finger, 1993). In conclusion, our perpetuation as a civilisation depends upon our becoming more compatible with the nature around us. Even without a knowledge of the principles of perpetuity and compatibility, it expression is still found in statements such as that "a sustainable society is defined as one that meets its needs without impairing the ability of future generations and other species to meet theirs" (Chiras, 1994).


This material is collated from ideas expressed in Nature's Holism. Return to Perpetuity and Compatibility section, as part of condensed version or the section on models in the quick tour.


Google



Search For:
Match:  Any word  All words  Exact phrase
Sound-alike matching 
Within: 
Show:  results  summaries
Sort by: 
Nature's Holism

Search the Nature's Holism site, throw in a word and see what you get!

Please support this work.

Order Nature's Holism Today!

DO AN INTERNET SEARCH, SEARCH THE WHOLE WEB, GO TO SEARCH.HTM Site map

Valid HTML 4.01!