Popular Science Monthly/Volume 42/February 1893/Man in Nature
|MAN IN NATURE.|
MAN is an animal, by the same title with other animals, without any more rights than those conferred upon him by virtue of the law of the strongest, by his physical organization, his physiological attributes, and his success in the struggle for existence. His body is of the same substance, is composed of the same tissues, and possesses the same organs. His forms are simple variants, produced by the same force that urges other beings to differentiation. Like every animal, he participates in the everlasting round of being born, reproducing, and dying. He was such when Galen dissected the ape to study it, and he has continued the same, resembling the ape in some respects and differing from it in others, subject to the same wants, the same physical experiences, the same instinctive impulses, the same inner feeling urging him to take everything to himself. In consideration of the highly developed properties of his cerebral organ, of his judgment, which permits him to see things exactly as they are, of his memory, which enables him to store up observations and draw inductions of the whole from them, of his routine-breaking initiative, and of his ideal conceptions, he may by a turn of mind regard himself as forming a separate kingdom in the Cosmos. But, in his body he is and always will be an animal—a vertebrate, a mammal, a monodelph, a Primate. None of the characteristics of these groups is wanting in him; eminently none of those of the Primates. He possesses peculiar characteristics which give him a special place of favor among them; but he begins by having their general characters.
"Then," you will tell us, "you place man by the side of the monkeys, of those beings which are often so abject. Could you not find a nobler animal?" That is prejudice, judgment by appearances. The monkeys are not disinherited beings, but the contrary. Some of the ungulates—the deers and the horses—have reached a high grade in the scale of the mammals: we esteem them because of the perfect adaptation of all their parts to an ideal of existence; their forms are elegant, their paces are graceful and rapid; they render us service while contributing to our pleasures; they are the last efflorescence of a branch which has been growing and blooming since the Eocene epoch. Some of the carnivores, like the cats, are likewise objects of our admiration for the complete harmony of their whole organisms to their peculiar modes of life; they have power, nobility, and freedom. But neither of these possess what the humble monkeys have—a cerebral type, predicted among them all from its origin, and already developed in the ugliest among them. The brain of the horse, nearest by virtue of its less rudimentary anterior lobe to that of the Primates, is rude, notwithstanding its well-formed convolutions, in comparison with that of the simians in general. Even the skull of the monkeys has something human, and reflects the interior cerebral organ. The brain has been evolved in all the branches of the tree of the mammalia, and at the end of some branches is elaborate in its convolutions, sometimes surpassing that of man in their richness. But in only one branch, that of the monkeys, does that exist from the beginning which gives the brain a special value, and causes them eventually to excel, whether the number of convolutions be equal or unequal.
We are amused with the monkeys, without remarking how marvelously they too are organized for their peculiar mode of life. We see them sporting, grimacing, swinging from one branch to another, and performing the most incredible feats of real acrobats. But we do not reflect that these habits, these necessities of their existence, are precisely what has given rise to the organ to which man owes most, after the brain—the hand. That hand, which by a curious aberration had in some of the marsupials abandoned the anterior for the posterior extremity, still occupies that extremity in the lemurians. In the monkeys it returns to take possession of its natural place of election, there to perfect itself gradually and to result in the incomparable apparatus which has caused Franklin to define man as "the maker of instruments."
The brain and its accompanying type of skull, the hand and its annexes the nails, are the characteristics which have produced the privileged situation of those animals which are correctly grouped together under the designation of the order of Primates. With some modifications in the proportions of the limbs to height and some accessory characteristics, their variants give place in them to divisions ranging from the lowest up to man. These divisions, whatever may be their relative value and their respective distances, are five: The lemurians—the monkeys of the New World, or the cebeans, from which the arctopithecans are sometimes separated; the monkeys of the Old World; tailed monkeys or pithecans; tailless or anthropoids; and man. A question which we had set before ourselves, and which had been much discussed in the Société d'Anthropologie, was whether the anthropoids of this list are nearer to the pithecan and cebean monkeys or to man. Shall we place in the same group monkeys and anthropoids or anthropoids and man? The question was then one of measuring in some way the interval between these anthropoids and man and comparing it with the subsequent intervals between the lower monkeys. From the result came the adoption of one or other of the rival systems of classification, some separating man from the Primates as a special order, others isolating him among the Primates as a suborder or family, and others including man and the anthropoids together. We said we must draw up a general balance sheet. As the divergences sometimes pertain to what we consider only one aspect of the problem, it was necessary to regard all the aspects; and we have done this. We have given our conclusions respecting each characteristic, respecting each group of characteristics. Our present purpose is only to summarize the most affirmative of them, those that concern the brain and the skull, the adaptation of the body, and particularly of the lower limbs, to the bipedal attitude, and of the upper limbs to prehension.
In the general type of the brain we have only determined common characteristics in what concerns the profound structure.
The type of the convolutions appears to us rudimentary in the lower Primates; gradually developing, already characterized in the papion; absolutely established, according to Broca, in the gibbon; becoming more complicated in passing from the anthropoids to man, but without appreciable change to a characteristic which must not be neglected, the transformation of the third frontal convolution. Man alone presents the speech centre, a characteristic corresponding with the acquisition of the faculty of articulate language. The conclusion results that, even without regard to the richness of man's convolutions, there still exists between him and the anthropoids a difference—capital in its physiological consequences—which forbids any relation on this ground between them and him. As to the volume of the brain the conclusion is express. It is triple in man and leaves the anthropoids with the other monkeys.
The consequence of this increase of volume, general, but predominant in the anterior lobes, is the complete transformation of the skull. While it retains some of the characteristics peculiar to the Primates in general, which it had already assumed, it becomes what we know it in existing man, profoundly different in all its characteristics from the skull of the anthropoids, including the craniometrical characteristics. The face itself is transformed. All bends before the supremacy of the organ which, near or far, governs the whole human organism and separates it completely from the anthropoids.
The hand is the second fundamental characteristic of man, but a characteristic common to all the Primates, starting with the first ones and advancing continually toward perfection. With the monkeys, the forearm comes to the aid of the hand; with the anthropoids, the whole fore limb concurs in the function; in man it acquires its final degree of precision. Till then it was simply a grasping apparatus related to tree life. With him its operations are associated with those of touch, sight, and the muscular sense, and it becomes the faithful executant of the orders of the brain. Is there anything more wonderful than the movement imperceptibly and gradually impressed by the fingers on the screw of the microscope in micrometrical operations? The hand, therefore, relates the anthropoid to man, but more in appearance than in reality, for in the anthropoid it still remains the brutal grasping apparatus of the monkeys.
The last characteristic is that of attitude. It is complex in the monkeys, similar in some respects to that of quadrupeds generally, but really special. Signs of the erection of the trunk are already manifested in some monkeys—as, for instance, the cynocephalus. This erection is emphasized in the anthropoids, but without reaching the upright position, and really permitting standing on the feet. With them the characteristics leading to that attitude bear on little else than the viscera and the vertebral column. They are inappreciable in the head, and are hardly more marked in the lower limbs, where the calves, thighs, and buttocks, characteristic of the effort necessary for keeping the upright position, are wanting.
Contrary to what has been said, the anthropoids are less qualified to hold themselves erect than the other monkeys. These can walk on the ground with extended sole; the anthropoids are less able to do so. The monkeys had in the lower as well as in the upper limbs a hand competent to act as a foot. This hand is improved in the anthropoids in the direction of its function of grasping, but to the detriment of its accessory function as a foot; in the lower limbs it is turned in in such a way that the palm can grasp a tree by the side, but can only painfully set itself on the ground upon its outer edge, and very likely, too, upon the backs of the toes. The hinder hand, therefore, hollows out a gulf between the anthropoids and the monkey; but the gulf between man and the anthropoids is wider.
Cuvier's reasoning was correct. The monkeys, and still more the anthropoids, deserve the name of quadrumana on condition that we do not understand the word hand in the rigorous sense that is given it in the case of man, but in the sense of an instrument that adapts itself to some kind of prehension. To us man alone has two real hands, as he alone among the Primates has two feet capable of supporting the entire weight of the body standing. When we suppose that the anthropoid is in a stage of advance toward a vertical position, we confound in him characteristics relative to the adaptation of the arm and forearm to the prehensile function and characteristics relative to the vertical attitude. If we suppress the former and whatever bears upon the straightening of the trunk in arboreal life—a straightening which in no way implies a vertical position of the lower limbs—there is nothing left particularly to the credit of the anthropoids. The other distinctive characteristics of man and the anthropoids are secondary, but lead to the same conclusions. Hence the two groups should be separated in classification, and the anthropoids continue monkeys.
Employing Dalley's formula, we should say, but in an inverse sense, that the anthropoids differ from monkeys infinitely less than they differ from men. We need not even specify from what monkeys, whether pithecans or cebeans, for it is sometimes members of one, sometimes members of the other family, that are more removed from man. In the general shape of the skull, in a certain adaptation to the erect attitude of the head, in the development of the hemispheres above the cerebellum, and in still other characters, some of the cebeans are further advanced than the pithecans and the anthropoids. In short, taking the interval between the cebeans (arctopithecans excepted) and the pithecans as one, that between the pithecans and the anthropoids would be one, and that between the anthropoids alone or the cebeans, pithecans, and anthropoids together and man would be three.
Reasoning according to the monophyletic hypothesis, we suppose that man is derived from a single stock. But the possibility is suggested of his having had a multiple origin from different stocks, and possibly at different epochs. To determine this point, we must learn what the comparative study of races teaches us concerning the unity of the human species in the present and the past, from the lessons afforded by the actual remains of the races that have been produced by incessant minglings and changes during a succession of ages that defy all chronology.
We have shown that there are, properly speaking, no races within mankind such as we find among animals—that is, constant varieties, perpetuating their likes in a certain manner. There are only historical or philological elements of peoples to which we attribute, whether rightly or wrongly, a certain number of common physical characteristics. In any other sense the races of anthropology are simply products of our minds, suppositions of substantial affiliations of unmixed blood, working hypotheses. There are no persons corresponding with the types we assume.
These types themselves are not tangible realities, but groupings of characteristics which we suppose to have been continuing for an indefinite time through the events of history and prehistory which, without destroying the characteristics, have not ceased to scatter them and to arrange them anew in different combinations. As Lamarck has said, types are products of art; we pick them out as we can in existing populations. From particular types we rise to the notion of general types, which are likewise only probabilities, going up gradually to historical, prehistorical, and Quaternary types, and, by inductive constitution, to primitive types. Hence the necessity of a classification of types; or, to use the current erroneous language, of races. Every anthropologist has his classification. M. Deniker in his, published in 1889, admitted thirty types; in the classification of our lectures and our Eléments d'anthropologie générale we enumerated nineteen, without concealing the existence of many gaps. This is all not very favorable to the idea of the unity of the human species. But it must not be forgotten that a number of these types are artificial, provisional, and, as we have said, simple mental views. Whether these were originally one or many types, the results are the same. At present all men are capable of unlimited crossing, and new types are in continual formation. If we would go up to the origin of things, we should have to put away all these secondary products and simplify more and more. We should thus come, in the first stage of our synthesis, to the conception of eight general types, viz.: A fundamental European blonde type, a Mediterraneo-Semitic, a brachycephalic Asiatic, a dolichocephalic Asiatic, an Americo-Polynesian type, a black type with curly hair, a brachycephalic negro, and a dolichocephalic negro type. But perhaps dolichocephaly and brachycephaly are only secondary differentiations that may be produced in all the types, as large and small stature may be too; the black man with curly hair may be only a cross.
Nothing is easier, in fact, than to conceive in the light of anatomy and physiology that all types of mankind can be reduced to three original types—the Europeo-Semitic, the Asiatico-American, and the negro; or to two—the white, which is differentiated into those of flat and of sharp faces, and the negro. A further reduction would be hazardous. But if we lost ourselves in the depth of the ages, we might conceive the negro as first born and giving birth in succession to the curly-haired Australian, to one of the brown forms with straight or waving hair, and finally to the blonde European.
Hence, the monogenistic system, or the doctrine of the unity of type and origin, and the polygenistic system, or the doctrine of plurality of type and origin, are equally tenable.
But, it may be said, prehistoric skulls and bones should assist us in our task. Only a little! With the single exception of the Neanderthal skull, which has a type of its own, all the few specimens which the prehistoric peoples have left us are obviously only duplicates of existing types, and those of Europeans and Americans. Of the ancient negro, Africa and Oceania, which were supposed to be the promised lands for primitive anthropology, have furnished us none. The most ancient man known to us by his bones is that one of Spy, which dates from the epoch of the mammoth. Yet it is demonstrated by flint implements that man primarily existed in both hemispheres. We see him, as the great Quaternary glaciers of Europe and America retired, going up toward the north. Europe was then only a narrow promontory which man traveled along in coming from Asia. That is all we know about our primitive ancestors. Beyond that we have no sure trace, no flints. The flints of Thenay are of the Roman epoch. To hazard a few conjectures respecting the Miocene ancestor, whether it was man or a precursor—one or the other certain, although direct proofs are wanting—we should be obliged to recur to the general probabilities furnished by natural history.
As we have seen, natural history proves indisputably that man is the issue of a Primate. It is opposed to the idea that we are descended from an anthropoid like those of the present time, although one of them—the chimpanzee—offers, perhaps, fewer objections to the supposition than the others. It furnishes arguments very favorable to the supposition that our stock comes from a Miocene monkey. It is not contrary to the theory of a direct descent from the lemurians, which were in their turn issue of the marsupials. But nowhere does it permit us to discern whether man came from one or two stocks, or originated at one epoch, or two epochs remote from one another.
The question whether the monkeys are of single or multiple origin is likewise not answered. According to MM. Vogt and Schmidt, the monkeys of the New World had not the same derivation as those of the Old World. This doctrine would support the theory of man having two origins, one common to Asia and America for the white and yellow races, the other on some southern continent joining Africa and Oceania for the negro.
Whether the moment of this origin be single or double, two periods are to be considered: one previous to the acquisition of language, in which the precursor of man is concerned; and the other after this, during which the real man was constituted. With the acquisition of speech a new life begins. Man, more able to associate with his fellows and to come to an understanding with them, would spread, become cosmopolitan, face every kind of climate, meet various necessities of existence, and thereby differentiate himself. This differentiation was all the easier, because his species was of more recent formation and less fixed, and because the media acted with certainty under those conditions. From that time the brain increased, the skull was transformed, prognathism diminished, and the facial angle opened.
But a new factor intervened at the same time. Till then the struggle for existence had been carried on by physical force; now it is sustained "by intelligence, and those with the best "brains win the victory. While it is doubtful whether Darwin's natural selection can, in the existing conditions of the globe, engender new species separated by physiological barriers, it is certainly very efficacious to the improvement of the types within the species, and it constitutes one of the most powerful factors of progress. In this way to mediocre types have succeeded more and more favored types, whether by the general conformity of these forms to the aim to be met, or by the development of the brain in conformity to the increasing wants of man, and to the various kinds of life which he has made for himself. Adaptation, that marvelous natural force that rules the organic world as universal attraction rules the inorganic world, has performed its part as to him as well as to all animals—to each in view of its peculiar kind of life. With man the peculiar kind of life is the intellectual life.
We may illustrate the relations of man, the anthropoids, and the monkeys by comparing the order of Primates to a tree. The lemurians are the roots, giving rise to one or several stocks. One of these is the stock of the monkeys, one of the limbs of which sends up a higher branch—that of the anthropoids. Another branch, of which the point of its origin or contact with the preceding branch escapes our search, gives the actual human branch, which rises parallel to the anthropoid branch, has no relation to it, and passes beyond it.
Has man reached his culmination? Is he at the end of his evolution, or is he a little short of it? Will he suffer the fate of the paleontological species, which, having reached the maximum height of their lives, halted and perished, or will he continue to advance? Will his senses acquire greater delicacy, his hand more readiness? Will his brain gain in volume, or in convolutions, or in the number or the quality of its cells?
We doubt, regarding the equilibrium of the head and the harmony of its parts, whether the brain will gain greatly in volume. Its anterior lobes may perhaps increase till the axis of gravity passes the middle of the base of the skull. Dolichocephaly will be replaced by a universal brachycephaly. The quality of the cells is sure to improve. On that side no limits can be discerned, and in that direction man may hope to reach the Buddhist's ideal.
When man shall have thus been exalted by his intellectual faculties, the lower types nearest to him will have disappeared, and those animals which are now most closely related to him will be no more, and the interval between him and the other types will have widened to an unfathomable gulf.
Man, with some show of reason at last, intoxicated with his power, and looking down from his giddy height, may come to fancy that he is a being without limitations, the center around which the universe gravitates, the sovereign for which all Nature has been created. He will, in fact, constitute a separate kingdom—the human kingdom.
Even then, in the midst of his triumphs, his body will continually call him back to himself, and the anatomist will still be able to cry to him, in words but little changed from an expression of Broca's, "Remember that you are one of the animals!"—Translated for The Popular Science Monthly from the book L'Homme dans la Nature.