The History of Biological Theories

This is the time that gives us our first distinct traces of the existence of man ; there are his coarse stone tools, his drawings of the bones of animals long extinct ; here and there, though not often, we find human bones. Most of these facts were known to Lyell. In later years French investigators discovered many caves which contained the traces in the form of his tools of primitive man ; they found many such caves both in France and in Spain. Very soon they had worked out criteria for distinguishing be- tween various periods in the evolution of pre-historic man ; these criteria were derived from an examination of his

stone implements. The periods in question were the so- called Palaeolithic and Neolithic ages, the age of Bronze and the age of Iron; recently these periods have been further subdivided. Some French and Belgian anthropologists believe that they can discern traces of even more primitive tools tools used by men of the tertiary epoch, that is, by men who were living in France before the Ice Age, during the warm period referred to above. Others think that these stones, the so-called 'eoliths', are not the work of man, but that they have been heaped up in certain areas by natural means, and hence they do not believe in tertiary men.

It is quite certain that men were alive during the Ice Age, and that they were contemporary with animals which have long been extinct ; but whether there have been men in Europe since the beginning of that epoch, or whether they only appeared during its course, is still a subject of discussion. Ice-age man lived on the edges of the glaciers, together with mammoths, rhinoceros, and other extinct creatures. He probably clothed himself in skins and hunted wild animals. He may have driven them into some pit or abyss and then have collected their dead bodies; he also killed his victims with stone weapons. He lived in caves or in tents, and he had discovered fire. He had developed a certain artistic sense; he used coloured earths to paint pictures of animals on the walls of his dwelling, and he pricked out the contours of mammoths, of deer, and even, of men, on the bones and pieces of horn which served him as weapons.

We do not know where was his home before he came to Europe, nor what became of him later ; whether he died out, or whether his descendants lived on as the most ancient people into Palaeolithic and Bronze Ages. With very few exceptions, our study of prehistoric man does not take us back across the threshold of the human. The oldest known men were already of the human type, both in appearance and habits. They are further removed from apes than they are from modern man. The science of comparative anatomy has seemed so important that the philosophers of evolution have devoted most of their attention to anatomical considerations, and have attached very little importance to the historical facts.

The aim has always been to show that man, in his bodily structure, is not very far from the animal. Since the mentality was regarded merely as the result of certain nervous structures, it is obvious that mental differences would be looked upon as of minor importance. This like- ness of man to the animal creation, because of the im- portance it assumed as a definite 'proof ' of the theory of evolution, became a favourite subject with scientists in the second half of the nineteenth century, and these discussions roused the fury of the anti-evolutionary party.

Yet, before that time, the likeness had been accepted as a matter of course. It had been observed by Aristotle. Ennius had already said Simia quam similis, turpissima bestia, nobisl Galen studied the monkey to understand human anatomy. So great was the conviction that the two are absolutely similar that Vesalius introduced a reform by bringing proof that Galen was mistaken, and that the monkey is not anatomically so very close to man. It is very instructive to examine illustrations of monkeys published in the eighteenth century, at a time when com- parative anatomy was already an established science, and when monkeys were well known. In these illustrations they look just like hairy men, have intelligent faces, stand on their hind-legs, and carry a stick or a flower in their hand. Such pictures are to be seen in Buffon's works, and religious sensibilities were not affronted ; the resem- blance of man to the monkeys was accepted as obvious. Buffon defines an anthropoid ape as *an animal without a tail, with a flattened face, with teeth, hands, fingers, and nails like those of man. It walks on two legs. This

definition excludes every tailed animal, every animal- faced creature, every animal with curved or pointed claws, all those who walk on four legs rather than on two/ Linnaeus placed man in the same order as the monkeys without encountering opposition. Lord Monboddo dis- cussed the question of the origin of man from monkeys. De la Mettrie hoped that one day we should succeed in teaching monkeys to speak and to behave ! Kant's anthro- pology ends on a similar note. The morphologists of the early nineteenth century also discussed this question of the similarity between man and the animal creation.

Meckel published a detailed description of certain human monstrosities (1862). He used his hypothesis that man during his development from the egg passes through the lower and higher animal forms to explain the resem- blance of these monstrosities to animals. This even explains why human monstrosities have occasionally been born with the heart of an insect, a reptile or a fish. Blumenbach described another group of monstrosities, in which he thought the human embryo resembled a frog. He, too, believed that such aberrations were to be ascribed to disturbances during development. Geoffrey extended his inquiry into 'unity of plan', and applied the idea to human structure. He described a series of human abnormalities to prove that parts of the human body are identical with corresponding parts of the animal body.

Nobody found such theories startling, for no one re- garded mere bones as the final criterion. What did it signify if man possessed all the structures which are found in the animal body, and exhibited no single one that was peculiar to himself? All that mattered was the harmony, the unity of those structures, the idea which they made manifest. And so they laid stress upon man's upright gait, upon the structure of his hand and of his foot, upon his intellect and his morality upon the 'ideal' in human life.

his day, when men were beginning to abandon idealism, but had not yet accepted materialism, they gave an ideal interpretation of the fact that men very closely resemble monkeys. Buffon devotes many pages to discussing similarities of men and monkeys. He shows that, if we compare the monkey with a primitive human type, instead of with civilized man, this similarity merges into an almost complete identity. We sec, from our description of the orang, that, if we consider structure only, we might regard it as the highest animal, or, with almost equal justification, as the lowest man. For, not taking the soul into account, he lacks nothing that we possess ; and in regard to bodily structure he is certainly nearer to man than to those other animals whom we also call by the name of monkey. If we consider structure only, we might quite well regard the race of monkeys as a variety of the human. The Almighty did not choose a new mould upon which to fashion man ; He made him after the model from which He made the animals. Men and animals alike embody one great design. But into this material, monkey-like body He breathed His divine spirit.'

It is not difficult to find traces of Descartes 5 philosophy in this a philosophy which regarded the soul as an addition to the body, as something which could be sepa- rated from it. That philosophy considers the soul as all- important. But, directly the materialistic aspects of this philosophy were emphasized, the belief in a soul lost all foundation 'ideas' became mere empty words, 'facts' became all-important. When this interpretation had become the common one, the doctrine of the relation between man and the animals assumed a very different aspect. 'Since he is so similar in body he is an animal' was now the assertion.

The difference in structure between thumb and big toe seemed, to the older writers, to prove that the hand of man was always predestined to fulfil special functions. In the newer view this difference simply represented an adaptation to new functions. And so the German material- ists especially Vogt (1863) asserted very emphatically that there is no essential difference in structure between the human body and that of the monkey. Huxley gave further arguments in favour of this assertion. Richard Owen had already pointed out the similarity. He was an idealist, convinced of the importance of the human reason ; this gave him a foundation for his belief that Man is fundamentally different from all animals. Now the new philosophy regarded the soul as merely a product or function of the brain. Thus Owen was driven to try to discover bodily attributes which differentiated men from the apes. He pointed out that, in Man, one portion of the brain (Pes Hippocampi Minor) is much more highly developed than in the monkey; that in him it assumes a totally different form. 1 On this anatomical ground he placed Man in a separate division of the animal kingdom, the Archencepkala.

Huxley was already prejudiced against Owen. He took advantage of the opportunity to declare his opposition publicly. He asserted that there is no essential difference between the apes and Man. 'The structural differences between Man and Man-like apes certainly justify our regarding him as constituting a family apart from them ; though, inasmuch as he differs less from them than they do from other families of the same order, there can be no justifica- tion for placing him in a distinct order. . . . All the abundant and trustworthy evidence which we now possess leads to the conviction that so far from the posterior lobe, the posterior cornu, and the hippocampus minor being structures peculiar to and characteristic of Man, it is precisely those structures which are the most marked cerebral characters common to Man with the apes.

'The structural differences which separate Man from the gorilla and the chimpanzee are not so great as those which separate the gorilla from the lower apes.' 2 These words of Huxley raised a storm of controversy. So much were the times changed ! A hundred years earlier 1 R. Owen, 'On the Characters, Principles of Division, and Primary Groups of the Class Mammalia,' Proc. Linn. Society, 1857. men of science had taught that man only differs from the ape in the structure of one organ ; this organ was not the Pes Hippocampi, however, it was the Intermaxillary bone. In 1786 Goethe had asserted that man possesses this bone, but no one considered that this fact altered the place of man in Nature ; all that disturbed Goethe was that people did not pay enough attention to his discovery. Now Owen, the follower of Goethe, denied this principle while the opponents of idealism were defending it. They did so, convinced that thereby they were founding a new philosophy. We are reminded of the sigh that escaped from Goethe during the discussion of the intermaxillary bone:

'I can well believe that the man who is an academic by profession would swear away all his five senses ; for he is not concerned with the living idea he only wants to know what other men have said about it.' In the Origin of Species Darwin had indicated that his theory might also apply to Man; in 1871 he set forth his views in the Descent of Man. Various motives induced him to take this step, though Lyell and Wallace, his supporters in the controversy, had objected to this ex- tension of the evolutionary theory. The book created another sensation, though it is not as great a work as the Origin of Species. The earlier work contains many of Darwin's own observations, while in the Descent of Man he discusses anthropology, sociology, medicine and philoso- phy without having any very exact knowledge of any of these subjects. It is not very surprising, therefore, that his examples are not always apt, his arguments not always scientific, and his conclusions not always sound.

Darwin taught that Man has been gradually evolved from some lower form of life ; that he is akin to the animal both in body and in mind ; that he has many rudimentary organs which are reminiscent of his animal structure. Like the animals, man undergoes variation; these variations are inherited. He is also subjected to the Struggle for existence'. Darwin's psychological explanations form the best part of the book, for here, more than in other parts of it, he is describing his own observations. He believes that Man is only a glorified animal, even on the spiritual plane. He admits that Man stands well above the animals, but there are great differences between the mentalities of animals between, for example, that of a dog and that of the simplest fish. Man shares his sense organs with the animals ; hence he must have the same primitive sensations. Many of his instincts, too, he shares with them the desire to live and to increase his kind ; mother love ; the child's instinct to suck at the breast, &c. Looking at the reverse side of this picture, the animal feels joy, pain, happiness, misery ; the young of dogs, cats, and sheep like to play, as do human children. Animals can be bad-tempered and ambitious; dogs have also a certain sense of shame and a certain modesty. Monkeys are discomfited when men laugh at them. Dogs possess imitativeness in a high degree; they have concentration, memory, phantasy, understanding, and the ability to learn the use of tools. They even have a form of speech. Darwin's dog, when he barked at a sun- shade which was moved by the wind, showed the beginnings of religious feeling, and he regarded his master as a god. He was also subject to remorse!

This was the first attempt to note in what ways Man and the animals resemble each other an attempt un- hindered by scruples or mental reservations taking simply evidence derived from first-hand observation. Darwin's discussion of the origin of Man was extremely inadequate. He constructed a genealogical table which began with the Tunicates and Amphioxus, and passed on through the Reptiles, Marsupials, and Monkeys. This only differs from Haeckel's in that it is expressed with greater caution. He describes how Man has reached his present position as the result of natural and of sexual selection.

Darwin attached great weight to sexual selection and attributed the origin of speech to it, as also the ability to sing, the loss of hair, the differentiation of mankind into divers races, and so on. Many treatises have been written since the days of Darwin dealing with the resemblances between men and monkeys, but no very important facts have been added to the discussion. We may, therefore, at this point, briefly summarize the more important features which are charac- teristic of the human body, and point out the views of anatomists concerning them. The most striking human characteristics are : a large brain and the head shape which goes with this ; a chin ; fleshy lips ; a nose which projects from the face ; the feminine breast ; the soles of the feet ; the non-hairy body ; the upright position ; the form of the hand with fully opposable thumb; a continuous row of teeth (in the monkeys there are spaces between the teeth) &c. Anatomists assert that some of these characters are of minor importance, e. g. the fleshy lips ; that others occur in certain animals, e. g. some monkeys have a projecting nose; that others, again, have arisen because of man's peculiar mode of life, e. g. the characteristic soles of the feet, the upright position, the large brain. They further point out that certain organs are vestigial in man and better developed in animals for example, rudimentary muscles for moving the skin, ear-muscles, vestigial tail vertebrae, and so on. They attach importance to certain atavisms which occur occasionally: men with more than thirty-two teeth, with a rudimentary tail, a hair-covered body, and similar abnormalities.

More recently there was an attempt to prove that human blood is chemically very much more akin to that of the anthropoid apes than to that of the lower monkeys ; I further, that the embryo in utero is attached by a single 1 R. Wiedersheim, Der Bau des Menscben als Zeugnisfiir seine V ergangenbeit, Leipzig, 1887. In this book he gives a list of rudimentary structures found in animals which show some resemblance to definite human characteristics. Grun- baum, in The Lancet of 1902, discusses the blood-relationship between men and monkeys.

placenta in both man and the higher apes, while in the old-world monkeys it is attached by two placentae. But the subject no longer claims attention. We have grown used to having the similarities between men and monkeys pointed out to us, and the arguments have lost their original freshness. The evolutionists were always hoping that something intermediate between man and the monkey would be discovered. At one time they looked for this link among primitive races of mankind, at another among human fossil remains.

While little was known about them, uncivilized peoples were described by travellers as extremely brutalized. In the eighteenth century there was a very general belief in the existence of completely savage and bestial men. Even Linnaeus divided mankind into two classes Homo sapiens and Homo ferus and, according to his definition, the members of the latter class were four-footed, dumb, and hairy! Such ideas have been discarded nevertheless this much is certain ; that some races are on a lower plane than others, both anatomically and mentally. The aborigines of Australia may be cited as an example.

On this account most of the evolutionists who investi- gate human origins believe that these peoples represent the forerunners of 'intelligent 5 man, or that they are close relatives of those forerunners. Haeckers genealogical tree may be given as an example of this type of speculation. 1 Like all such trees, this has been criticized ; other writers would express the relation- ships between the various peoples differently. Some (Schoetensack, Macnamara) think that the cradle of humanity was in the islands of Melanesia; Ameghino seeks it in South America, Klaatsch thinks it will be found in Europe. Kolmann suggested that the first men were

1 I cite, in a simpler form, Haeckers tree showing the pedigree of Man from the 5th edition of his NatUrL Schopfungsgescbicbte. dwarfs, and that these gave rise to two dwarf races a black race and a yellow one, who only gradually attained their present stature. Americans Esquimos Finns Magyars Semites Indo-Germans | | | | Basques Caucasians The affinity with monkeys is not universally admitted. Klaatsch, for example, suggested that Man had evolved from a marsupial ; this marsupial forbear had first of all de- veloped certain simian characters, and then it evolved into a very primitive human type. He thought that modern apes are a degenerate stock, representatives of abortive deviations from the direct line of human evolution.

This study of the comparative anatomy of living races was eclipsed by the interest aroused when fossil remains of prehistoric man were first discovered. Virchow was certain that the bones found were those of real men who had lived in a community. He found on these bones the traces of wounds that had healed, also the marks of disease, and he said they gave obvious evidence of human care; when more skulls were found, however, this contention was shown to be untenable.

In 1856 the so-called Neanderthal skull was discovered in a cave near Diisseldorf ; this had a very low forehead and very pronounced frontal ridges. These discoveries made Virchow less certain of his position. Subsequently in 1901-2 Gorjanovic Kramberger discovered the oroken remains of ten similar skulls at Krapina, in Croatia ; these showed the same primitive Neanderthal characters in- deed, they are perhaps even more primitive. In 1907 Dr. Schoetensack discovered a perfect lower jaw of the pre-Neanderthaloid type, in a cave near Heidelberg Homo Heidelbergensis. This fragment prob- ably dates from the second Interglacial period.

The Java ape-man Pithecanthropus erectus was dis- covered in 1891 by the Dutch observer Eugene Dubois; the remains consisted of two teeth, a part of a skull, and a left thigh bone. 1 Dubois and others described this creature as intermediate in structure between the ape and Man hence the name ; it seems to belong to the upper Pliocene or the lowermost Pleistocene period. The remains of another fossil man were found in France, with characters apparently intermediate between those of Neanderthal man and Pithecanthropus erectus. This man must, however, have been partially civilized, as he was found in an artificial grave. More recently there has been the very important discovery of Rhodesian man.

There has been great progress in the study of physical anthropology since Darwin's time, for many new facts have been discovered. But the methods of this science are still the methods of the Darwinian school. In this respect it lags behind other branches of biology which have tried to strike out along new paths. 1 Haeckel invented the name Pithecanthropus. Dubois thought that his dis- covery was a form intermediate between Man and the ape, and he would have placed it in a special family. Schwalbe submitted these bones, which Dubois had discovered, to an anatomical investigation. Voltz and Selenka affirm that Pithec- anthropus represents a fairly advanced human type a type living socially.

present inhabitants of the earth, especially those JL who are civilized, are linked up into societies, held to- gether by ties of nationality, of language, territory, religion, custom, and history. Philosophers and politicians are not agreed as to which of these spiritual ties is the most im- portant. The result of the view that man is only a higher animal, that his soul is the product of his body, has been that, during the latter half of the nineteenth century, special importance has been attached to the anthropo- logical and biological aspects of racial problems.

Man is one species, with several varieties. There is no general agreement as to either the number or character- istic features of those varieties. J. Blumenbach (1752- 1840), the founder of the science of physical anthropology, divided mankind into five races Caucasian, Mongolian, Ethiopian, American, and Malayan. Modern anthro- pologists divide him into many more races, and link these up into groups. Thus E. Fischer classifies as follows: III. The group inhabiting the Oceanic Islands. The Negritos, Malays, Dravidians.

IV. The group inhabiting Australia and the Southern Pacific Islands. Australians, Melanesians, Micronesians, and Polynesians. V. The East, Central, and Northern Asiatic group. Japanese and 1 See 'Anthropologie' in . Hinneberg's Kultur der Gegcnwart, 1921. characters belonging to several of the above groups ; this was said to be due to crossing between the groups. Stimu- lated by Virchow, attempts were made in Germany, Austria, Belgium, and Switzerland to demonstrate this mixture of racial types among school children. The colours of hair, eyes, and skin were examined, and the examination gave the following results :