Competition

The Struggle for Existence

In Chapter 3 of Origin, after two chapters discussing variation under domestication and in the wild, Darwin abruptly launches his war of nature:

A struggle for existence inevitably follows from the high rate at which all organic beings tend to increase. Every being, which during its natural lifetime produces several eggs or seeds, must suffer destruction during some period of its life, and during some season or occasional year, otherwise, on the principle of geometrical increase, its numbers would quickly become so inordinately great that no country could support the product. Hence, as more individuals are produced than can possibly survive, there must in every case be a struggle for existence, either one individual with another of the same species, or with the individuals of distinct species, or with the physical conditions of life. It is the doctrine of Malthus applied with manifold force to the whole animal and vegetable kingdoms; for in this case there can be no artificial increase of food, and no prudential restraint from marriage.
(Darwin. On the Origin of Species. 1st ed. 1859 Ch. 3)

What is notable about this Darwinian struggle for existence is that it is a struggle of one individual with another. As Malthus had described it, rising human populations resulted in an increased workload, not an outbreak of civil war. The Malthusian struggle for existence meant, simply, increased toil.

This war of nature was perhaps Darwin's most enduring contribution to the theory of evolution. What had been seen, until then, as a harmonious natural order, became a bloodbath. And in the rest of Origin, Darwin rams home the image of struggle, war, murder, extermination.

Food concentration and dispersion

Nature may be compared to a surface on which rest ten thousand sharp wedges touching each other and driven inwards by incessant blows
(Darwin. Linnean Society 1 July 1858)

It is not particularly hard to see where this idea comes from. Given more mouths to feed than the limited amount of food available, the image is easily conjured of hungry, jostling, struggling animals, wedged together, biting and tugging and trampling over each other to reach that food. And, given this image, it is clear that the strongest, fastest, and most aggressive are likely to come out the winners. And, indeed, that an animal would increase its chances of survival if it took to actively exterminating its competitors.

But hidden in this vision of competition is an unstated supposition that the natural world provides its bounty in a concentrated and localized form - as if Nature, like a farmer, feeds the creatures by unloading its produce in one great pile, in a particular place and a particular time, before the hungry livestock. In this artificial circumstance, as they all rush in, direct competition is inevitable.

But the natural world cannot be compared to a farmer filling the feed troughs of his livestock. The produce of nature - leaves, seeds, fruits - is dispersed, at different times, across the surface of the land. And consequently those creatures that feed on this produce must be generally equally dispersed across the land. In this circumstance, all wedging and fighting and trampling vanishes. Competition disappears.

It is man, with troughs, and granaries, and birdtables, who creates localized concentrations of food, and thereby creates competition. And it was in an a man-made English countryside, with granaries and troughs and birdtables, that Darwin lived for most of his life. Here an English country gentleman has watched pigs fighting to reach the trough, birds sqabbling at the bird table, and extrapolated this competition to the entire natural world.

This is not to say that food is always dispersed in nature. In some circumstances, food resources are highly concentrated and localized. The carcass of a large animal is a concentration of food on which several scavengers may converge. And the result may well be that one scavenger drives off another. But such activity is only justifiable when the jackpot of energy in the carcass far exceeds the amount of effort required to drive away a competitor.

In order to underline their grim conviction, the apostles of competition must always describe the natural world as if nutrient energy were concentrated in localized packages. They never deal with the density of dispersed food, but always with the absolute amount of food. Thus:

The sun parcels out the energy and plants turn it into food. But provisions are limited: there's only so much acreage where plants can grow, only so much sunshine and so much fuel. Anything that wants it has to fight for it.
(Prisoners of the Sun. BBC TV. 2 Feb 1992)

Here the sun, which shines evenly and equally upon the land, is made to "parcel out" its energy, as if sunshine dropped in great lumps from the sky. And there's "only so much" of these lumps of sunshine, so the plants must be contrived to somehow "fight" for them. In actuality plants only capture some 2% of incident solar radiation, wasting the remaining 98%, which suggests that rather than there being "only so much" sunshine, there is actually far too much.

Indirect Competition

Occasionally, what is meant by competition is spelled out:

Competition is an interaction between individuals, brought about by a shared requirement for a resource in limited supply, and leading to a reduction in survivorship, growth, and/or reproduction of the competing individuals concerned.
(Ecology. Begon, Harper, Townsend.)

The many millions of cells that make up a human body all have a shared requirement for a resource in limited supply - the glucose, oxygen, and amino acids carried in the blood stream. Occasionally, blood sugar levels may fall low enough to affect the survival of cells. Are we then to suppose that the cells in a human body compete with each other, and that the life of these cells a struggle for existence, one with another?

The resource for which individuals compete must be in limited supply. Oxygen, for example, is not something for which grasshoppers or grass plants compete; the supply exceeds the rate at which the densest population can consume it. Similarly, light, food, space or any other resource is only competed for if it is in limited supply.
(Ecology. Begon, Harper, Townsend.)

Apart from food, another essential prerequisite of animal life is oxygen. And this is dispersed yet more evenly in the atmosphere. Hence there can be no competition at all for oxygen. Yet in this case, it is said that there is no competition because there is an abundant supply of oxygen. This suggests that if the concentration of oxygen in the atmosphere were to decrease, falling from its present level of 21% to 10%, that some sort of competition would ensue. But whatever the level of oxygen, there never could be competition between any creature as to who is to have this or that particular O₂ molecule. What will happen, as oxygen levels fall, is that those creatures unable to live at low levels will die, and the remainder will survive. This entails no competition between them at all.

Anyway, in a field full of grasshoppers:

Each grasshopper will frequently find itself at a spot where there had previously been a blade of grass - before, that is, another grasshopper ate it. Whenever this happens, the grasshopper must move on... The more grasshoppers that are competing for food, the more this will happen.
(Ecology. Begon, Harper, Townsend.)

But when a grasshopper finds itself at a spot where it has it itself just eaten a blade of grass - as it regularly and inevitably will -, then it must also move on. It is perfectly possible for a single grasshopper to itself consume all the grass in a field, if that field is small enough, and the grass grows slowly enough. Thus each grasshopper must be its own strongest competitor, its own worst enemy.

The most that can be said is that in such a field, the grasshoppers act to reduce the density of grass in the field. As they do so, they must work harder to acquire nutrient energy. At some point, some grasshoppers will become unable to survive. This may be because they have higher energy demands than others, or less effective search strategies, or simply fall victim to bad luck.

In many cases, competing individuals do not interact with each other directly. Instead, individuals respond to the level of a resource, which has been depressed by the presence and activity of other individuals. Thus grasshoppers competing for food are not directly affected by other grasshoppers, but by the reduction in food level and the increased difficulty of finding good food that has been left by the others...
(Ecology. Begon, Harper, Townsend.)

Here direct competitive interaction has vanished, but the grasshoppers are still described as "competing". The term "competition" can only be meaningful if competing involves some sort of activity on the part of the grasshoppers other than their normal, non-competitive behaviour - such as driving away other competitors, stealing their food, pushing them aside, etc. If a state of "competition" entails no change in the behaviour of the supposed competitors, then the term is redundant.

Niche Specialization

A more common objection to competition is that the creatures do not all feed on the same homogenous food, but specialize in eating different kinds of food. Thus while cattle graze on the grass in a field, some small birds will look for small seeds between the stems, and others pull up worms from below - each finding its own niche in the economy of nature. In this case, because each is searching for a different source of food, competition is avoided.

This is a variant of the dispersion argument. But instead of food being dispersed in location, it is dispersed in kind.

The Energy Cost of Competition

If it is accepted that where food resources are concentrated in a particular locality, and that direct competition ensues among those creature that converge upon it, then the participants in this competition must minimize their competitive effort. For if a competitor expends 100 KJ of energy in driving off, or killing, another competitor in order to win a prize worth 10 KJ, then the effort of competition has resulted in a net loss of 90 KJ - and the "winner" is a loser. Competitors must expend less energy in competing than the amount of energy they win. Two cows would be fools to fight over a tuft of grass. Or, rather, such tough, competitive, dynamic cattle are long extinct.

Competition - fighting, trampling, etc - also must be minimized in order to avoid physical damage. The competitor who emerges from competition with torn ligaments or a broken leg is unlikely to compete successfully again.

Direct competition for food is only likely when food resources are concentrated in time and location. Such competition becomes increasingly improbable as food resources become dispersed in location and type. In the stream-fed population simulation, nutrients are concentrated at one end of the stream, and some degree of direct competition may result. In the pool-fed population simulation, nutrients are dispersed across a field, and little direct competition results.

Altruism

In the Darwinian competitive system, the constant attempt of all creatures must be to drive away, exclude, even kill other competitors. In such a world, any kind of altruistic behaviour, offering assistance or aid, carries a death penalty. That animal which defers to another is doomed to be brushed aside and left to starve. Thus any sort of altruistic behaviour presents a puzzle for the devotees of competition.

In competition-free Idle Theory, by contrast, altruism is unremarkable. As field energy densities fall, the creatures work harder. It is the most hard-working creatures that first succumb, while their more idle companions survive. There is no need for the most idle to compete at all for food, but merely to wait until energy densities have fallen to a level where the least idle can no longer survive.

And if at the nadir of such a crisis the least idle are working continuously, while the most idle are hardly working at all, then it is perfectly possible for an idle and altruistic creature to not only give way ("After you") to their toiling fellows, but also to actively assist them. For the most idle can devote, if they choose, some of their idle time to work on behalf of their less fortunate companions, bringing them food they would otherwise be unable to find.

That the most idle can assist the least idle does not, of course, mean that they will regularly do so. They may not be able to assist. They may not see the need for assistance. And if they do assist, they can only save a minority of the least idle from extinction.

Conclusion

If food is only available in the natural world in localized concentrations upon which the creatures converge, then direct competition for food must result. Yet in this case, the creatures must act to minimize their competitive efforts, lest they expend more energy in competing than they finally win.

But, very generally, the sun shines evenly upon the earth, and thus plants are dispersed evenly across its surface, and those grazing or browsing animals that feed on plants are also dispersed across the land, along with the predators that prey upon them. Rather than being locally concentrated, food resources are dispersed. This dispersion results in minimal direct competition. It becomes very unlikely that one browsing animal will reach for the same leaf at the exact same time as another.