MAN, EVOLUTION OF. The late Sir E. B. Tylor, writ ing on the evolutionary theory of man's origin, made the following statement : "In one form or another such a theory of human de scent has, in our time, become part of an accepted framework of zoology, if not as a demonstrable truth, at any rate as a working hypothesis which has no effective rival." When Sir Edward Tylor made this statement in 1910 he was in his 78th year; his memory could carry him back to a time when it was believed that man had come into the world as a special creation some 4,00o years before the birth of Christ and owed no kinship to other living things. He was 27 years of age when Darwin's Origin of Species was pub lished in 1859; in 1865, two years after Huxley had issued his re nowned treatise on Man's Place in Nature, he himself published a work which threw a new light on human history, Researches into the Early History of Mankind and the Development of Civiliza tion. When Darwin's Descent of Man came out in 1871, Tylor's Primitive Culture; Researches into the Development of Mythol ogy, Philosophy, Religion, Art and Custom, kept it company. By the end of the 19th century he had seen chair after chair in the universities of the world filled by men who were convinced that evolution was true; at his death in at the age of 85, he had seen another generation of enquirers grow up who, after applying Darwin's teaching to all departments of man's world—to his body, mind and culture—remained convinced that, as a working hypoth esis, the doctrine of evolution had no rival.
Embryology.—No matter what aspect of man the student of to-day may select for study, the conviction that evolution (q.v.) is true is forced on him. If he investigates the development of the child in the womb he comes across a complicated series of appear ances which can be explained only if Darwin's teaching is ac cepted.
Comparative Anatomy.—If he studies the structure of man's body he finds it framed on the mammalian plan, and if he com pares it with that of anthropoid apes he finds the points of resem blance to be so numerous and so close that he cannot think that such a degree of resemblance could be a result of mere chance. If he enquires into the periods through which a newly born child passes to reach manhood or womanhood, he finds the animals which are most human in this respect are the great anthropoids— the gorilla, chimpanzee and orang. If he takes into consideration the diseases to which man is liable, he finds that human diseases are more readily communicated to the great anthropoids than to any other living animals. Particularly is he impressed by the fact that the blood of man and of the anthropoid apes, when tested against each other, react almost in the same way. To account for the presence of so many vestigial structures in man's anatomy, he feels impelled to suppose that man has come of an ancestry in which these vestiges were fully grown and useful. A child may be
born with its body malformed; it may suffer from hare-lip, clef t palate or many other kinds of deformity, including the presence of a tail; medical men cannot account for such malformations if they look on man as a special creation ; they can give a rational explanation of their occurrence if they accept evolution.
Palaeontology.—In recently formed strata of the earth fos sil forms of man are found; those from the older strata are more ape-like than those from the newer. In still older strata are found fossil fragments of great anthropoids ; in still more ancient, the remains of small anthropoids; deeper still in the earth's records no trace of anthropoid has yet been discovered. In these older strata occur fossil remains of small monkey-like primates. The geological records, so far as they are yet known, support Darwin's theory of man's origin ; they are altogether against the belief that man appeared suddenly—by a special act of creation.
Human Races.—More especially is the student of human races driven to Darwinism for an explanation of his many prob lems; even if he believed that man had appeared originally by an act of special creation he must formulate a theory of evolution in order to account for the divergent races now living. Although in thought and deed man rises far above any member of the brute creation, yet students of his brain find that it is modelled, part for part, on exactly the same pattern as that of the anthropoid ape. Those who enquire into man's mental qualities, his emotions, his habits, his tendencies and his modes of thought, find many indi cations that he has ascended from a lower order.
But there are still numbers of unconvinced people who, impressed by the great and real differences which separate the mentality of the lowest grades of mankind from that of the high est grade of ape, cannot believe that man has arisen from a lower form by any natural or evolutionary process. The State of Tenn essee has passed a law forbidding, in State-supported schools, "the teaching that man has descended from a lower order of ani mals." In June 1925 Scopes, a school teacher, was prosecuted under this law, found guilty and fined $1oo. Since then certain other States have enacted similar laws. Even in England, Dar win's native land, the theory of man's origin from an ape-like ani mal is far from finding universal acceptance. This was made ap parent in 1927 when the writer, being then president of the Brit ish Association for the Advancement of Science, made Darwin's theory of man's origin the subject of his address. Although the opinions expressed were those held by the vast majority of an thropologists, they were met with a strenuous opposition on the part of a large section of the public.