An evolutionary and ecological consideration of the use of rural resources by Homo sapiens

by David J. Curtis & M. Angela Curtis

Note: This essay was originally presented as a paper at a conference held at the University of Pau in south-west France, 21-24 July 1992: the Third European Forum on Nature Conservation and Pastoralism, jointly organised by David Curtis (University of Paisley), Eric Bignal (Joint Nature Conservation Committee) and Clause Dendalechte (University of Pau). It forms a chapter in the proceedings of the conference: Nature Conservation and Pastoralism in Europe (1994), ed. E.M. Bignal, D.I. McCracken & D.J. Curtis, ISBN 1 873701 60 8, published by U.K. Joint Nature Conservation Committee.

Abstract

This brief essay is intended as a concise consideration of Man's position in relation to his environment. It is expressed in terms of evolutionary, ecological and psychological/sociological concepts, consistent with the status of the species Homo sapiens within the global biosphere of the earth. It is concerned with concepts which must not be forgotten when we struggle to cope with the demands for correct management of our rural (and other) resources.

Introduction

This forum is concerned with the quality of the environment, particularly in relation to the support which is needed for birds of pastoral systems. We are thus concerned with the patterns of land-use which interact with the "natural" conditions prevailing in the life-ranges of these species. These patterns of land-use are determined to some extent by (a) human society's resource needs and demands for products of rural activities (i.e. by consumers), (b) the practices which are involved in the actual production of these resources (land-users), (c) economic and commercial influences (business and economics), (d) the planning and legislative framework in which these operate (planners and lawyers), (e) the political systems which generate the laws (politicians) and (f) public opinion which influences the behaviour of politicians seeking re-election in democratic societies (the general public, educators, propagandists, media).

All of these diverse, but inter-related determinants of environmental quality vary tremendously between different European countries, between different regions within countries and certainly between different types of landscape and farming systems. However, they do share just one common factor - the species Homo sapiens and this essay looks at this species from an evolutionary and ecological viewpoint.

Evolutionary aspects

Mankind is a product of biological evolution over a very long time span. Zoologists would place this species near the top of one of the two main evolutionary lines of multicellular animals:- the Protostomia and the Deuterostomia (Fig. 1). This follows the schemes considered by, for example Hyman (1940, 1951) and described in basic zoological texts such as Barnes (1980).

If we accept the conventional biological interpretation of the development of life on earth, we can envisage the development of relatively simple unicellular organisms (Protozoa amongst the animals). From these Protozoa developed multicellular animals, the Metazoa, whose bodies are more efficient as they could specialise cells (and thence tissues, organs and organ systems) for particular functions, at the expense of providing coordinating and transport systems around the body. Clearly, this was successful as the vast majority of animal species are multicellular. While the most primitive Metazoa had no body cavity (termed acoelomate), more advanced Metazoa developed a coelom (a fluid-filled space between the gut and body wall) which evolved separately in the Protostomia and in the Deuterostomia.

The protostomian line of evolution led to the arthropodan phyla, including the insects - a vast array, possibly millions, of species which are often quite specialised in their environmental requirements, as are many of the other invertebrate animals. Overall, individually each of these species has a relatively small impact on the overall planetary ecosystem.

In contrast, the deuterostome line of evolution led to the vertebrate animals, including the mammals in which there is an order called Primates. The Primates have a sub-order Anthropoidea, within which is a superfamily called Hominoidea, which can be divided into two families: Pongidae, the apes, and Hominidae, Man (all living races). A very readable and clear treatment of human evolution is provided by Turnhaugh et al., (1993).

Thus there is a single species Homo sapiens at the present culmination of the deuterostome line of evolution. Whilst the Primates already existed in the Palaeocene era (65 million years ago), Homo sapiens has only been around for one or two million years. This species is an extreme generalist in terms of its environmental requirements, being able to survive just about anywhere on the planet (or even off it) given enough technical support. This species also has tremendous wide-ranging impact on its environment (and thus on the environment of other species, in spite of (or perhaps, related to) its very recent appearance on the evolutionary stage. This has important implications for the ecological consequences of our actions.

Ecological aspects

This evolving set of living organisms, of which the animals considered above form only a part along with plants, fungi, bacteria and viruses, constitute the biosphere. The biosphere can best be regarded as the layer of matter over the surface of the planet which engages in complex interactions resulting in the persisting set of phenomena which we call 'life'. These living organisms are able to maintain themselves as distinct entities separate from the non-living (or abiotic) components of their environment (on a planetary scale, the lithosphere, hydrosphere, etc.). They are also able to reproduce, giving new generations of organisms similar to (but not identical with) themselves.

According to the view of Bock & von Wahlert (1965), who were concerned with the role of ecological factors in evolution, each of these organisms can be considered as a set of features, each of which has both a form (what it is) and a function (what it does). Similarly, the environment within which the organism lives can be considered as a set of factors (some obvious, some very subtle) which influence its life and, in evolutionary terms, can be regarded as selection forces, determining the reproductive success of the organism and thus its contribution to the evolution of the species. The combined form-plus-function of a feature is termed its faculty; when this interacts with a selection force in the environment it constitutes a biological role and the term synerg was coined by Bock & von Wahlert to label this interaction between a feature of the organism and a single component of its environment. The overall integration of all the synergs makes up the ecological niche for that organism, i.e the organism- environment relationship which is the subject of changes taking place during evolution. This concept emphasises that an organism only exists in so far as it interacts with its environment.

The ecological niche may also be considered in terms of the range of conditions over which an organism can survive and reproduce (i.e. in terms of its evolutionary fitness), which reflects itself in the abundance of a species over a range of environmental conditions. It is possible, following the ideas of Hutchinson (1957, 1959), to envisage the distribution of a species relative to many factors in its environment. This constitutes a 'multi-dimensional niche', with a dimension corresponding to each of the important factors. A 'specialist' species has a narrow range along one or more of these ecological dimensions and possibly only few dimensions to its niche. A 'generalist' species has an extensive range along one or more of its niche dimensions, of which there may be many. A generalist species is likely to have a greater impact on the species with which it shares the environment.

Homo sapiens is a generalist species, par excellence.

The Noosphere

The most significant feature of Man is the ability to think and work with theoretical constructs. With the tool of language, the possibilities for inheritance are extended from the biological: based on nucleic acids in the genetic code, to the exosomatic: educational and cultural. This could be seen as the result of our increasing complexity, resulting from our evolutionary past and certainly relating to the large number of nerve cells in our brains and the consequent complexity and flexibility of behaviour.

Essentially, this increase in complexity has extended the evolutionary and ecological theatre of Man from the biosphere (realm of life processes) up to the noosphere (realm of thought). The noosphere is a concept developed by Pierre Teilhard de Chardin (1965, 1969; English translations of earlier editions), which relates to the advanced evolutionary position of Homo sapiens. He used the term 'reflexion or reflection' to indicate two aspects: (i) ecological and behavioural: the ability of men and women to realise what they are doing, through the power of thought and (ii) evolutionary: with the result that we are strongly influencing our own evolution through this.

We are also influencing our environment, thereby affecting our organism/environment relationship (niche) and thus our own evolution. In Hutchinsonian terms, the dimensions of our ecological niche extend beyond the physical and chemical to the psychological and spiritual.

Psychological aspects

As a corollary of this extension of Man's world, we can see that there is an increase in the range of needs which each person must satisfy. These are related, not only to individual development, but also to our individual positions within the social framework. Maslow (1973, 1987) has described this in terms of a `hierarchy of needs' in relation to human personality (Fig. 2). These needs ascend from purely biological up to the spiritual. He listed five types of needs, the first four of which are basic or 'deficiency' needs, which can be satisfied under the appropriate circumstances.

These five types of needs are:- (1) The most basic need is physiological, related to survival, food, drink, sleep, basic sex - i.e. aspects which are firmly within the biosphere; ascending the other needs takes us gradually into the noosphere. (2) Next comes the need for safety, not only physical and economic (i.e. biosphere) but also psychological security (partly biosphere, partly noosphere). (3) The need for love and belonging includes affection, intimacy and roots in family or social group (partly biosphere, partly noosphere). (4) At a higher level, we have a need for esteem, in terms of competence, adequacy, respect by self and by others (perhaps more noosphere than biosphere). In contrast, the highest level of need is for self-actualization - "becoming what one is capable of becoming", i.e. fulfilment, which for many is a spiritual matter. This was regarded by Maslow as a 'being' need, with no end-state, simply the expression of the need is an end-point in itself.

Implications for rural resource use

Our efforts to manage and conserve the wider countryside can be viewed at different levels. We need to maintain a viable environment, one which can support our own species and other species as well. In many rural landscapes, the long-term use of traditional practices, especially extensive and pastoral agriculture have contributed to the habitat diversity and hence the biodiversity of the countryside, supporting a rich flora and fauna in which birds are often seen as the most impressive indicators of environmental quality.

Within this context, it is important that a positive attitude is adopted. All too frequently, conservationists are seen as "applying the brakes to development" and being backward looking. We should have confidence in our actions, and work positively to combine development with the maintenance of environmental quality, for ourselves and for other species. In the words of Teilhard de Chardin (1964), "the whole future of the Earth, as of religion, seems to me to depend on the awakening of our faith in the future".

At a fundamental level, it is necessary to satisfy the most basic of needs in Maslow's hierarchy, preferably within the context of sustainable environmental management. Only if these basic needs are satisfied can people hope to satisfy their higher-level needs. We also, then, need to pay attention to the aesthetic qualities of our environment. This has relevance in two ways. A visually pleasing landscape is able to "please the heart as well as the eye" (Magnus Magnusson, 1991) and thus fits in with Maslow's basic needs, as well as contributing to our well-being at the higher level of the noosphere.

More importantly, greater acquaintance with the natural world leads to an awareness that each of us is a component of the ecosystem which surrounds us; thus the living world around us is essentially an extension of our individual selves. In realising this, we are only accepting one aspect of Maslow's highest level of need: self-actualization. In caring for our environment, through sensitive management of rural resources, we are really only caring for ourselves.

References

Barnes, R.D. 1989. Invertebrate Zoology. (4th. edn.) Holt- Saunders, Philadelphia.

Bock, W.J. & von Wahlert, G. 1965. Adaptation and the form- function complex. Evolution, 19: 269-299.

Hutchinson, G.E. 1957. Concluding remarks. Cold Spring Harbour Symp. Quant. Biol., 22: 415-427.

Hutchinson, G.E. 1959. Homage to Santa Rosalia, or why are there so many kinds of animals? American Naturalist, 93: 145-159.

Hyman, L. 1940. The Invertebrates. Vol. 1. Protozoa through Ctenophora. McGraw-Hill, New York.

Hyman, L. 1951. The Invertebrates. Vol. 2. Platyhelminthes and Rhynchocoela. McGraw-Hill, New York.

Maslow, A.H. 1973. The further reaches of human nature. Penguin, Harmondsworth.

Maslow, A.H. 1987. Motivation and personality. (3rd. edn.) Harper & Row, New York.

Magnusson, M. 1991. Foreword. Curtis, D.J., Bignal, E.M. & Curtis, M.A. (eds.) Birds and Pastoral Agriculture in Europe. (Proc. 2nd European Forum Birds & Pastorlism). Scottish Chough Study Group.

Teilhard de Chardin, P. 1965 (& 1980). The Phenomenon of Man. Collins, London. (& Harper-Collins, New York).

Teilhard de Chardin, P. 1964 (&1969). The Future of Man. Collins, London (& Harper-Collins, New York; also Fontana, London).

Turnhaugh, W.A., Nelson, H., Jurmain, R. & Kilgore, L. 1993. Understanding physical anthropology and archeology. West Publishing Company, Minneapolis/St. Paul.

Footnote:-

During the field excursion at this conference, travelling from the humid low altitude French countryside over the high Pyreneean passes and down to the arid plains of Spain, the delegates were impressed by the scale of natural ecosystems and inspired to consider thoughtfully Man's place therein.

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