Many authors, dating back to Darwin (1871), have considered factors that might affect the degree of sexual dimorphism (reviewed by Clutton-Brock, Harvey & Rudder, 1977; Mace, 1979). Frequently, however, only one sex is considered, or it is unclear what limits the degree of sexual dimorphism. For example, intermale conflict is believed to select for increased male size (Darwin, 1871; Selander, 1972; Trivers, 1972). However, larger females achieve greater reproductive success (Chapter 4) and Rails (1976a) has argued that this may be why females are sometimes larger than males. On the other hand, Erlinge (1979) and Moors (1980) have argued that smaller females enjoy a bioenergetic advantage.

It is not yet clear what sets an upper limit to male size in species where males compete over females, and larger males enjoy a competitive advantage. One possibility is male-biased mortality. In many species where males are the larger sex, mortality is greater for males than for females (Potts, 1970; Selander, 1972; Clutton-Brock & Albon, 1982). Selander (1972) argued that the greater mortality of male great-tailed grackles, Quiscalus mexicanus, occurs partly because males are more vulnerable to predators, and partly because males are above the optimal size for efficient foraging. Another possibility, suggested by Belovsky (1978) and Searcy (1979), is that larger males have less energy available for reproduction.

The greatest degree of sexual dimorphism, in species where males are heavier than females, occurs in pinnipeds (Scheffer & Wilke, 1953; Bryden, 1969). Bartholomew (1970) suggested three factors which might set an upper limit on male size in pinnipeds. First, larger males are more aggressive and in the most dimorphic species oblivious of the pups, so that many pups are squashed to death.

Organisms are adapted by natural selection to their physical and biological environments. Individuals differ within and between species in, among other things, such features as their body size, their age at first reproduction and the effort they put into growth and reproduction. The body of theory, generally known as life-history theory, that considers such features is extensive and growing rapidly (Stearns, 1980; Calder, 1984; Sibly & Calow, 1986). In a seminal review of these theories, and of the data that support them, Stearns (1976) concluded that we need more comprehensive theory that makes more readily falsifiable predictions. This view has been echoed by others (e.g. Peters, 1983). One way of viewing this book is to see it as presenting a number of life-history theories. I have tried to make the theories comprehensive, to make their assumptions explicit, to investigate the sensitivity of their conclusions to variations in the assumptions, and to test them whenever possible.

In common with most spheres of knowledge, the field of allometry has expanded very considerably within the last ten to fifteen years. It is perhaps no longer possible for a single text to provide a detailed review of all the work (see Peters, 1983; Calder, 1984; Schmidt-Nielsen, 1984). I hope this book has a single thread that runs through it, but I have tried to restrict myself to those areas where I feel I may have something new to contribute.

In essence, this whole book rests on two equations introduced in Chapter 2. These equations relate the scaling of average daily metabolic rate and energy assimilation intraspecifically to body weight, W.

Ecosophical consciousness and lifestyle

How would mankind's present role on this planet be evaluated in the light of philosophical world-views of the past? No matter which one of the great philosophies one considers to be valid, our current role would be evaluated negatively. It is in opposition to value priority as announced by these philosophies. This applies to Aristotelianism, Buddhism, Confucianism, and other great philosophies of the last two millennia.

In the great philosophies, greatness and bigness are differentiated. Greatness is sought, but it is not magnitude. The importance of technology is recognised, but cultural values get priority of consideration. The good life is not made dependent upon thoughtless consumption.

In the great philosophies, people are required to attempt to evaluate the distant consequences of their actions and the perspective used is to be universal in time and space. None of the great philosophers regarded market relations and modes of production as the source of norms for state, society, or individual. The importance of economic relations is recognised but seen as a fragment within the web of social relationships.

My conclusion is that there is no articulated world-view which endorses mankind's current role in the ecosphere. Environmentalism has no articulated philosophical system to fear.

But this does not furnish any potent consolation in the situation characterised in the opening of the book. The question must be raised: how are the ecologically destructive, but ‘firmly established ways of production and consumption’ (p. 23) to be changed?

The contact with total views

It has been said in the first chapter that what makes the ecological situation especially serious is that there is a deeply grounded ideology of consumption and production which is unecological. This kind of diagnosis makes it essential to analyse economic conditions and to consider a science with great influence, namely economics.

There is another motivation, namely that economics has traditionally a broad contact with total views with normative content.

Economy comes from the Greek word oikonomos: one that takes care of the household, a normative undertaking. So to be a good and wise economist is in this sense nothing terribly exciting, or special. Oikonomos is a word that may be put in contrast to cosmonomos: the nature and world administrator that very few beings can live up to. But already Xenophon, Plato, and Aristotle treated the household problems for the community as a whole, for polis. Xenophon was the first in a long series of thinkers who looked at economics from a rather narrow point of view. They became the ideological advocates primarily of the people who had property, the landowners.

Economics is, in the European tradition, often defined as the science of how to satisfy human needs. But since it clearly does not talk about every kind of need it becomes necessary to define ‘economic’ needs. What are these?

Introduction

While the phenomenological approach of the previous chapter was conducive to generalization, it is, almost by definition, impossible to generalize about the subject of this chapter. Since the mechanistic view includes such a wide variety of topics, from insect movements to shading to resource utilization, no single methodology is possible. Nevertheless, it is possible to group mechanisms into broad categories and discuss potential approaches within each of these categories.

Following the overall structure of this book, the mechanistic approach is presented in two broad categories, mechanisms of reduced competition and mechanisms of facilitation. Within the category of reduced competition are included two topics: partitioning the light environment, and partitioning resources. For the same reason that it was possible to develop an analytical approach to the environmental impact of one species on the environment of the other, in chapter 7 a potential engineering approach is possible when competition between two annuals is known to be for light. Since light is unidirectional, there are certain inevitable rules upon which one can build, at least provisionally. On the contrary, when competition is for resources no such inevitable rules are obvious.

Within the category of facilitation, above and beyond the clear planning implications of Chapters 4 and 6, which are not repeated here, there are three topics elaborated, all associated with pest control. First, the so-called ‘trivial’ movements of pests and predators, which is to say their movement patterns within a field after having arrived, are treated with the standard application of diffusion equations.

The first part of the chapter introduces a way of formulating the essential traits of a total view which could be of help to all who wish to verbalise their basic attitudes and compare them with others' – especially those who seem to oppose vigorous ecological policies. This portion is methodological, and not limited to my own particular view, Ecosophy T.

The second part attacks problems of ontology, ‘what there is’. Rather than talking about reality or the world, ecophilosophical thinking proceeds in terms of nature, and humanity's relation to nature. An attempt is made to defend our spontaneous, rich, seemingly contradictory experience of nature as more than subjective impressions. They make up the concrete contents of our world. This point of view, as every other ontology, is deeply problematic – but of great potential value for energetic environmentalism in its opposition to the contemporary near monopoly of the so-called scientific world-view.

The terms ecology, ecophilosophy, ecosophy

Those who come across these three terms should ask for precise definitions – but in the disorderly terminological situation we are placed in today, both descriptive and prescriptive definitions are somewhat arbitrary. In this work, the three words will have three very distinct meanings adapted to our purpose. Others, however, with other purposes, may disagree somewhat on these precise meanings.

Tropical travelers, from Darwin to my mother-in-law, will attest to the obvious fact that intercrops, two or more crops grown in association with one another, are common. My own travels in India, South-East Asia, and Latin America certainly offer no contradiction to this general rule. Quantitative estimates suggest that 98% of the cowpeas grown in Africa are intercropped (Arnon, 1972), 90% of the beans in Colombia are intercropped (Gutierrez et al., 1975), and the percentage of cropped land in the tropics actually devoted to intercropping varies from a low of 17% for India (Srivastava, 1972) to a high of 94% in Malawi (Edje, 1979). Apparently, in El Salvador it used to be impossible to find sorghum not intercropped with maize (Alas, 1974, cited in Pinchinat et al., 1976; Hawkins, 1984). Even in temperate North America, before the widespread use of modern varieties and mechanization, intercropping was apparently common (e.g. 57% of the soybean acreage in Ohio was grown in combination with maize in 1923 (Thatcher, 1925), and recently there seems to be increased interest in the subject, at least in the research community (e.g. Schultz et al., 1982; Putnam et al., 1985; Herbert et al., 1984; Allen & Obura, 1983; Shackel & Hall, 1984). Thus, by any standard, intercropped agroecosystems are common. Their diversity and overall distribution are illustrated in a partial compilation of combinations that have been cited in the literature, as presented in Table 1.1.