PART II RELATION OF MAN TO NATURAL CONDITIONS INTRODUCTORY NOTE The study of Part I of this volume will have acquainted the student with the main features of natural environment, especially with those which exert a strong and constant influence upon man - and so upon trade. Into this environment it is now proposed to introduce man, and to show how his life is conditioned by the factors of which an account has been given. It is manifest to one who has given but superficial attention to the influence, direct or indirect, of natural environment, that we can no more than sketch the most general and universal of these life conditions. Influence of natural environment is all-pervasive; but to attempt to pursue it into its finer ramifications would be to immerse the reader in a mass of detail from which he would very likely emerge with scarcely greater profit than from the consecutive reading of the dictionary.1 The next section of the volume will be devoted, therefore, to the most broad and general influences of natural environment upon man. And since man is an organic being, like those whose life and distribution have been studied, the method employed will consist largely in the application to man of the evolutionary reasoning just now (§§ 133 ff.) applied to the plants and animals. But, as any one can perceive with a little reflection, the cases are not absolutely similar; our main concern will be to show how the case of man differs from that of the flora and fauna by reason of the fact that he is so much more highly developed in brain power than are the lower organisms. 1 Geographers and anthropologists have given much attention to the relations of human societies to their regions. It is in the power of the teacher to interest students in the gathering of instances bearing upon the contentions set forth in succeeding chapters. CHAPTER VII HUMAN ADAPTATION. ENVIRONMENTAL INFLUENCES 138. Necessity of adaptation. Every alteration of any importance in their environment sets before the animal or plant, as has just been seen, a series of alternatives: death, degeneration, flight, or adaptation. What is the fate of man, the so-called highest of the animals, under the same conditions? It is well known that men die when natural conditions become unfavorable enough; famines recurrently sweep many from the earth. Again, they degenerate when they are forced to live a life that is possible to live, but only in a miserable way. Some of the lowest tribes of men, like the South African Bushmen or the Digger Indians, have been forced by stronger tribes to withdraw into the desert and to exist upon a lower plane of life. The physique of such peoples betrays the hardships which they have suf fered. Men also flee from an unfavorable environment, thus escaping death or degeneracy, if the way into a more favorable locality lies open for them. Much of migration and colonization comes under this alternative. The abandoned farms of New England furnish illustration of this topic: their former owners may be in the West, in the cities, or elsewhere where effort wins a subsistence or a comfort impossible under the old conditions. The Italians and other foreigners who are taking up these abandoned farms, whose ideas of a satisfactory standard of living are not so ambitious, may represent the level of life to which the emigrants were unwilling to descend. The alternative of adaptation remains; and this is the one which, for the time, occupies our attention. An animal species, instead of pursuing any one of the other courses, may so adapt itself as to get back into harmony with its environment. In a cold region, as has been seen, a coat of fur can be acquired; in deserts a regular ration of water can be renounced. Animals and plants perform physical adaptations to environment; and we observe the visible results of these adjustments and classify the lower organisms upon the basis of such characteristics. But how is it in the case of man? Certainly there has been little change worth mention in man's physique since the earliest records. The various local peoples, with their characteristic features, color, and so on, as we know them to-day, appear in Egyptian paintings of some 3300 years ago (1380 B.C.).1 Skulls and other human relics dug up from ancient strata might well be duplicated among men of to-day. Since man was man he has undoubtedly formed several races, variously distinguished on the basis of color, stature, and other minor physical differences. But the essential oneness and lack of important physical variation in man is conclusively proved by the inability of scientists to mark off genera, or even species, of men. And yet men are found under all sorts of natural conditions conditions to which other animals have had to adapt by physical modifications of considerable degree. Man is not exempt from the penalties of nonadaptation. How is it, then, that human adaptations are effected? 139. Intellectual adaptation. There is one respect in which the various human groups in the world can be, and are in practice, set apart one from the other, and by which men of to-day can be distinguished from men of preceding centuries. This is by a comparison of what we call their civilization. Now civilization is a complex affair, and is usually interpreted to include institutions, morals, literature, etc., which are but remotely connected with the struggle for life. For the present purpose we wish to refer only to what may be called material civilization, that is, to those mechanic arts, instruments, systems, and the like, which have given to man an increasing "power over nature." These arts and dexterities are plainly the result of brain activities on the part both of their originators and of those who have, through generations, contributed such additions and modifications as have rendered the original inventions better suited to the situation. Now the development of this material civilization performs for man the same services which actual physical adaptation discharges for plants and animals. Instead of growing a coat of fur in a cold climate, man retains the heat of his body by making himself an artificial garment, generally stolen from the adapted animal; instead of developing feet and hands suitable for climbing, he makes ladders and resorts to a number of artificial devices; instead of extending his reach, weighting his fist, and sharpening his claws through actual physical modifications, which would take generations upon generations to develop, he artificially and briefly accomplishes the same purpose by making himself a stone or metal axe. Weaker in body, slower of foot, duller of scent and sight, than his animal competitors, he becomes superior to them all through his capacity for mentally conceiving the requirements of a situation and taking immediate advantage of them. 1 A reproduction in color of such a painting may be seen in Ratzel's Hist. of Mankind, III, 162. We say that man "takes thought" in doing all this; and here is the key to his exceptional power of adaptation. Man does not adapt in any important measure through modifications of his hairy coat, his hands and feet, but through modifications of his brain and the secondary nervous system; and the measure of his intellectual adaptation is what we call his material civilization, his power over nature, his industrial organization. His tool or weapon is the visible form (realization) of his idea - his conscious mental adaptation. This sets man entirely apart from the rest of the animal world. Other animals die, degenerate, flee, or attain to adaptations of physical structure; man has done all of these things, but, as a rule, he evades them all, because of the high power of adaptation of his characteristic organ, the brain. Animals may increase in numbers up to the supporting power of their natural environment, which latter changes with no reference to their own activities; but man, though his numbers and characters are limited ultimately by the same conditions, may, by taking thought and developing arts and processes, contrive to extract more support out of the same natural environment or may even modify the environment itself in the direction of his own interests. 140. Physical versus mental adaptation. This point deserves some emphasis and illustration, for, as we shall presently see (§§ 181, 212), trade itself is one of the artificial methods developed by man, and man alone, in his struggle for existence and comfort. Let us imagine, for example, a small island in mid-ocean, from which neither man nor beast could escape by natural means. This relieves us of migration as an element in our problem. Suppose that this island will comfortably support twenty land animals, say, dogs, and that there are just twenty there. These dogs will devour, let us say, the entire food supply, each getting enough. Suppose, now, that the numbers are suddenly increased to twenty-five; what will be the result? The following possibilities will be open: (1) five die and twenty live in comfort as before; (2) twenty-five live on a lower plane of existence, i.e. have one fifth less food than before, degeneracy resulting; (3) twenty-five live because some or all can modify—for example, can learn to get and eat sea food. This last would in time mean actual physical change, say, toward the seal or otter type. But each physical change would demand generations of time and consequently a large mortality. The death of all but the strongest twenty (the first-mentioned possibility) would be the most likely result. Thus natural selection would operate (§ 135). Let us now make the same series of suppositions in regard to man. The first two possibilities stated above might hold with man as with animals. But instead of the third an arduous physical modification -we should find mental adaptation, which would speedily open up new sources of support or render the old more productive; for example, the invention of nets and hooks to catch fish, of snares or weapons to take birds or animals, of methods of treatment of soil which would render plant life more exuberant, and so on. Modifications allowing of growth of numbers, so slow in the case of animals as to call for a large preliminary mortality, |