THE EMERGENCE OF MAN

Otago Daily Times, Issue 17942, 22 May 1920, Page 4

THE EMERGENCE OF MAN

SIDELIGHTS ON HIS PATH OF PROGRESS. LECTURE BY DR BEKHAM. Tho third of Dr Benhom's lectures in tho University winter course on Anthropology was delivered in tho Museum Lecture Room last night. Tho professor addressed himself first to the question of where man first emerged from his pro-human ancestry. He showed! that much light could bo thrown on this by the study of Ihe geographical distribution of the past and present members of tho order primates. By means of maps _he indicated some of the great geographical changes through which tho land surface of the world had passed in various periods. New Zealand, for instance, was at one time part of a hugo peninsula from, a, continent, and at another was merely a group of small islands. Ho traced the spread of the lemur family as the story has been deciphered from various fossil and other remains. The mar jority of the genera of lemurs aro now found in Madagascar and on an island between it and! Africa, and he gave same of the reasons which lead scientists to assume tho existence at one time of the continent of Lemjuria stretching from Madagascar to India. In describing the distribution and migration of various types of primates at different geological periods he pointed out that orang-outang,s and gibbons were found in ' the Oriental region including Borneo, Sumatra, and Java which had all been united by land in comparatively rcoent geological times. In' Java also was found man's ancestor pithecanthropus. The generally accepted result of scientific investigations was that man had first emerged from his pre-human ancestry in Southern Asia. Tho lecturer dealt next with tho question of what factors of habit and environment have led to tho emergence of man from his pre-human ancestry. It was a very widespread) mistake to suppose that man had eter passed through a quadrupedal stage. At a very early period of its evolution the group of primates left the land and took to' climbing trees. ' There were fivo characters that marked off the primates as arboreal animals. These were the differentiation of arms and legs, the opposable finger and thumb, the shortening of the snout, the forward direction of the eyes which have now but one field of vision, and the great development of the brain, especially of the cerebrum 1 . He illustrated the differentiation of limbs by reference to various specimens and pictures, and discuFsedi the puTpostf of tho log and' arm and tho special adaptation of each to its own purpose. The hand of tho primates and therefore of man was of very ancient structure and has preserved its ancient simplicity. The lmmin hand, indeed, is more primitive than that of somo monkeys, in which the thumb is more developed. The exploring hand of man by_ moans of which he could satisfy his curiosity had been, a strong factor in his progress. So much waa this so that many held that the best method of educating the infant was by insisting on the constant use of the hand. He further illustrated the recession of the snout in an ascending series of animals, and 'explained the significance of this evolution. The more primitive raoes of men had more powerful molars, and tho wisdom teeth were of very little account. It seemed likely that the wisdom teeth might disappear altogether in a few generations. Some scientists even held out tho hope that we should at last develop into a toothless race. Turning to the brain the lecturer showed that its development could be traced from that of tarsius onwards with increasing complexity. Ho illustrated tho progress made in passing from the brain of the reptile to that of the mammal. It was the greater brain that hod enabled tho small mammals to overcome and eventually supplant the reptiles of small brain that had menaced them. In the lower vertebrates the sense of smell predominated, but as we ascended the scale the other senses supplanted it in importance. A most interesting comparative examination was made of the brain structuro of various animals ranging from very primitive types right up to man, and tho order and significance of this evolution was carefully explained. Physical perfection of adaptation was useless without the brain to take advantage of it, and similarly great brain ]jower was uselcsp without the physical perfection through which to act. Speaking of tho leading characters of man, ho eaid man was the product of a long lino of ancestry which was never compelled to turn aside in its evolution to the development oi protective devices. Three factors had each been held by different authorities to ba tho chief factor in the development of man from his simian ancestry—the erect posture, wlucii sot free the hands, the growth of speech and the growth of brain. The examination of each of these led up to' tho conclusion that most authorities now regarded tho steady growth and high specialisation of the brain as the fundamental factor in the progress of man upward. The leoturer turned next to the human embryo and baby, and drew attention to many remarkable evidences to be found there of human affinity with tho a lies as, for instance, in tlic infant's extraordinary power of grasp. In conclusion, tho professor briefly reviewed and summarised, the ground covered in his three lectures. The fact that man could trace his ancestry did not take away from tho beauty and truth of tho Psalmiet'B words, "Thou hast made him a little lower than the angels. Thou crownest him with glory and honour."