Social Environment and Moral Progress

by Alfred Russel Wallace

By far the larger part of the criticisms of Darwinism by popular writers are due to their continually forgetting these two great natural facts: enormous variability about a mean value of every part and organ; and such ever-present powers of multiplication that, even in the case of vertebrate animals, of those born every year only a small proportion—one-tenth to one-hundredth or thereabouts—live over the second year. If they all lived their numbers would go on continually increasing, which we know is not the case. Hence arises what has been termed "the struggle for existence," resulting in "the survival of the fittest."

This "struggle for life" is either against the forces of inorganic or those of organic nature. Among the former are storms, floods, intense cold, long-continued droughts, or violent blizzards, all of which take toll of the weaker or less wary individuals of each species—those that are less adapted to survive such conditions. In judging how this would act, we must always remember the enormous

scale on which Nature works, and that although now and then a few of the weaker individuals may live and a few of the stronger be killed, yet when we deal with hundreds of millions, of which eighty or ninety millions inevitably die every year while about ten or twenty millions only survive, it is impossible to believe that those which survive, not one year only but year after year throughout the whole existence of each species, are not on the average better adapted to the complex conditions of their environment than those which succumb to it. It is a mere truism that the fittest survive.

Exactly the same thing occurs in the case of the organic environment, to which each species must also be well adapted in order to live. The two great essentials for animal existence are, to obtain abundant food through successive years, and to be able to escape from their various enemies. When food is scarce the strongest, or those who can feed quickest and digest more rapidly, or those that can detect food at greater distances or reach it more quickly, will have the advantage. Enemies are escaped by strength, by swiftness, by acute vision, by wariness,

or by colours which conceal the various species in their natural surroundings; and those which possess these or any other advantages will in the long run survive. The weaker, the less well-defended, and the smaller species often have special protection, such as nocturnal habits, making burrows in the earth, possessing poisonous stings or fangs, being covered with protective armour; while great numbers are coloured or marked so as exactly to correspond with their surroundings, and are thus concealed from their chief enemies.

Natural Selection, or Survival of the Fittest

It may be here noted that the term "Natural Selection," which has often been misunderstood, was suggested to Darwin by the way in which almost all our varieties of cultivated plants and domestic animals have been obtained from wild forms continually improved for many generations. The method is to breed large quantities, and always preserve or "select" the best in each generation to be the parents of the next. This method, carried on by hundreds of farmers,

gardeners, dog, horse or poultry breeders, and especially by pigeon-fanciers, has resulted in all those useful, beautiful and even wonderful varieties of fruits, vegetables and flowers, dray-horses and hunters, greyhounds, spaniels and bull-dogs, cows which give large quantities of the richest milk, and sheep with the greatest quantity and finest quality of wool. All these were produced gradually for the special purposes of mankind; but a similar result has been effected by Nature through rapid increase, great variability, and continual destruction of all the individuals less adapted to the conditions of their special environment, so that only the strongest or the swiftest, the best-concealed or the most wary, the best armed with teeth, horns, hoofs or claws, those who could swim best, or those that protected each other by keeping in flocks or herds—lived the longest and tended to improve still further the next generation. "Survival of the fittest" was suggested by Herbert Spencer as best describing exactly what happens, and it is a most useful descriptive term which should always be kept in mind when discussing or investigating the process by which the

infinitely varied and beautiful productions of Nature have been developed. There is really not one single part or organ of any plant or animal that cannot have been derived by means of the fundamental facts of variability and reproduction from some allied plant or animal.

It is interesting here to note, that the two essential factors of the process of constant adaptation to the environment by great variability and rapid multiplication, formed no part of Lamarck's theory, which some people still think to be as good as Darwin's. Equally suggestive is the fact that, while extensive groups of life-phenomena, such as colour, weapons, hair, scales, and feathers, can hardly be conceived as having been produced or modified by effort or by the direct action of the environment, they are yet, every one of them, perfectly explained by the fundamental and necessary processes of variability and survival, acting slowly and continuously, but with intermittent periods of extreme activity at long intervals, on all living things.