Читать книгу A Review of the Systems of Ethics Founded on the Theory of Evolution - Cora May Williams - Страница 26

In the earliest forms of propagation, the younger organism is a true copy of that from which it springs, the trifling differences being due, as Schmankewicz has shown, to outer influences. The differences of male, female, worker, and soldier are due to such outer influences. The differences in the younger organism, where propagation takes place through copulation, may be explained by the mixture of types, through which, by action and reaction, some qualities are intensified, while some others become latent or are entirely destroyed. To these mutual influences are to be added such as come from without, especially those of warmth, and of quantity and quality of food. Under too great an increase in temperature, the young organism may even be destroyed, the process of assimilation not being able to keep pace with it. Those variations which have led to the development of existing forms, that is, which were favorable to life, are chiefly such as could be brought about by relative or absolute increase of assimilation. This is true of mental, as well as of physical, qualities.

It is a fact established without doubt, that the most common and most widely distributed species show the greatest variability, and that those species, on the contrary, which are now rare, although they were, perhaps, at earlier periods, the most common and extremely variable, vary, at the present date, the least of all. Following Darwin, one generally draws the conclusion that the severity of the struggle for existence favors the formation of varieties. For, it is said, the most common species fight the severest battle with one another, while the scanty representatives of rarer species come the least into competition and continue unchanged. But this theory is, in two ways, erroneous. In the first place, no attention is paid to the fact that a rare species may be exposed to a severe struggle against another species for the same nourishment, while a common species may, on the other hand, be exposed to no such struggle, and, supporting life from a generous supply of food, be subjected to but slight pressure. The conception of the Darwinians means nothing more or less than that the individuals of a species vary the more, the less favorable the conditions of nourishment; and this cannot be conceded. Again, the fact is to be taken into consideration, that the species at present common must have passed through a favorable period in which food was so plentiful that it not only afforded an abundance to individuals past the dangers of infancy and youth, but allowed, in addition, the existence of an ever-increasing number of individuals. And it is this period of increase, of abundance, not a period of struggle, which has developed the variations we now have before our eyes. In the same manner one must conclude, with regard to the rarer species, that the formerly existing numerous varieties were destroyed during the period of decline, that is, of overpowering pressure. We have abundant proof of this in the fact that domesticated species, which are carefully tended and fed, and so wholly withdrawn from the struggle for existence, vary enormously, and produce the most wonderful monstrosities.

To what direct causes the appearance of a variety is due, is a question as yet unanswered. But Weismann's investigations have shown us that climate plays a large part in their development. Embryology teaches us, moreover, that the development of the young organism does not take place with the same uniformity in all organs, but that, on the contrary, in one period one organ, in another, another, undergoes a more rapid growth, which may be influenced by variations in food or temperature. Through such variations the development of monstrosities is explained. We know that influences of nourishment are operative in the development of the larvæ of bees to workers or to queens, and we can easily conceive that other organs besides the sexual are subject to these influences. The field in which such influences may be operative is, indeed, boundless.

All these considerations lead us to the conclusion that variability in general, but especially that variability resulting in a so-called improvement of the varieties producing it, is an accompaniment of prosperous conditions. This is a conclusion not yet reached in zoölogy, although botanists long ago recognized, in abundance of food, the most essential condition for the development of variations.

Darwinism fails to account for any need of nourishment beyond that necessary for the maintenance of the status quo of life. According to Darwin, the animal can acquire only sufficient for the repair of loss. The struggle for existence is, therefore, according to him, a struggle of self-defence, and its results could be, at the best, only the maintenance of species in their present position or, in a less favorable case, their decline, and finally their destruction. But this view is wholly false. The animal acquires not only enough to repair loss, but much more. How could the first amœba have propagated itself, if it consumed no more than it needed for mere self-maintenance, and how could evolution have taken place? We have seen that, even in the inorganic world, there is not an equality of loss and repair, but that, in osmose, the denser fluid takes up more than it gives, while the fluid that is less dense loses more than it receives, and the mutual exchange reaches the maximum possible under the existing circumstances. It is this characteristic which renders the involuntary and forced tendency of the organism to satiation independent of the amount of waste; this mechanical hunger is the spring of the insatiability of organisms, and explains to us their increase in number, the process of increasing perfection, and individual development. Without it, an eternity would not have sufficed for evolution; we should still have only a world of primitive amœbæ.

This theory of development is, then, the opposite of that ordinarily assumed. The latter asserts that increase of growth demands increase of nourishment, whereas this asserts the fact that increase of nourishment determines growth. The struggle for existence is not a struggle for the mere necessaries to maintain life, but a struggle for increase of acquisition, increase of life; it is not a struggle of defence, but an attack which only under certain circumstances becomes a defence. The rule with which we advise our friends is, "Forward! strive to better yourself!" though we may endeavor, in hypocritical spirit, to persuade to contentment those who come into competition with our interests.

The chief points, therefore, in which this theory differs from that of Darwin, are as follows:—

"The struggle for existence is really a struggle for increase of nourishment, of life; and independent of the supply of the moment, it goes on at all times, hence even in a state of abundance.

"Limitation of supply by competition leads to fixation of the species and, in the end, to its decrease and disappearance.

"Sickness, climate, and direct enemies are the destructive agencies, and must secure more propitious conditions for survivors, the stronger their effect.

"Only under conditions of prosperity can the survivors propagate largely, and perfect themselves, separating into varieties and species.

"The increase and differentiation of the organic world shows us that conditions of prosperity have been the rule, those of want the exception."

Rolph's extremely interesting chapter on Propagation traces the sexual instinct to the "mechanical hunger." The earliest example which may be adduced in support of this theory is that of the zoöspores which, by copulation, sustain life for a time under the unfavorable conditions of darkness, the thinner male representing, as does also the spermatozoön, the seeking individual suffering from want, the female representing a means of sustenance. The sex of the young organism is in like manner referred by Rolph to conditions of nourishment during development. We now come to the chapter on