Evolution Of Man (1967)

[Music] millions of years ago manlike creatures lived on this East African plain in that time the land wasn't as Barren as it is today for this was the edge of a great lake then and many trees and other plants colored the land green but time changed all that and a few remains of those creatures that lived here long ago eventually were buried beneath this plain today scientists come to this very place to find out about man's past for subsequently a river came and cut a mile wide Gorge down into the plain the old Gorge uncovering the stone tools and fossilized bones that tell of man's life here finding any of this evidence of man's past is a long painstaking inch byin search over the surface of the land and then beneath it and the deeper into the gorge the scientists dig the older are the fossils that are discovered of course the odds against sifting an fossils from the tons of rock are fantastic to the untrained eye bits of fossil bone look exactly like bits of rock yet fosil are found broken bits and pieces of of what patient reconstruction of some of these fragments reveals the skull of an ancient man a man like ourselves and yet different to understand how modern man could have evolved from earlier man it's necessary to have some idea of how all living things may have evolved and changed Charles Darwin in two books the Origin of Species and The Descent of Man proposed his theory of natural selection to explain how the world had become filled with so many different kinds of living things with animals that live in the water amphibians that come from the water to live on the land with reptils and birds birds and mammals by Darwin's time fossil skeletons of saber-toothed cats had been found that were related to the modern cat family and fossil skeletons of woolly mammoths had been found that were related to Modern elephants but it wasn't until after Darwin on the tropical Asian island of java that a young Dutch Doctor Eugene dubis found and identified manlike fossils a thigh bone and the top of an ancient skull since then fossil records of about a thousand prehistoric individuals have been uncovered only a thousand not very many to reconstruct the story of man's Evolution and of these thousand individuals only a few are complete skeletons some are represented by just a single tooth the most durable part of a human skeleton some are represented by fragments of the brain case some by a Jawbone some by the complete skull to place these fossils of early man into any able order of evolution is extremely difficult because there are so very few of them and the time gaps between them are so large for example this skull belonged to a crow magnum man who lived in France perhaps 25,000 years ago crom magnan man is not very different from Modern Man this skull belonged to someone who lived perhaps 65,000 years ago between crom magnan and Neanderthal man Neanderthal man flourished in Europe 100,000 years ago and then about 35,000 years ago disappeared one of the earlier of the true humans is Homo erectus this woman lived perhaps 400,000 years ago near peing precise measurements of these few fossil skulls are taken so that one can be compared to another and perhaps some order of difference is discovered and some differences do seem clear the frontal ridge above the eyes is thicker the farther back in time we go when we trace the skull profile of relatively modern chromagnon man then compare it to the older skulls we can see some of the other changes the farther back in time we go the smaller the chin and more importantly the smaller the brain case especially the part that holds the forebrain that section most concerned with thinking because early human fossils are so rare scientists study each one carefully even the impressions of arteries and veins inside the brain case might offer some clues about the brain's activity fossil jaws and teeth may suggest something about their owner's age and diet these belong to an adult female these are the milk teeth of a child about 6 years old it was with the discovery of this particular skull in South Africa that the story of man's ancestry reached back to the very line between man and preman this is Australopithecus who lived 2 million years ago this is one version of what he might have looked like this another no one can be sure which if either is right and which was he man or near man where is the line crossed to answer that means we would have to agree on what man is and what we mean by the word human and there is no such agreement as we move still further back in time we come to a creature called proconsul that lived 25 million years ago then much further back 70 million years back to the time when primates first appeared in the mammal line creatures that might have looked like this present day tree shrew now in Tracing Our ancestry it's essential to understand that these tree shrews are as modern as man and no animal living today is actually an ancestral type but some of these modern mammals do suggest what some of the ancestral primates probably looked like suppose the first primates were small shrew likee animals like this that lived in trees what sort of evolutionary pressures could have caused some of the descendants to remain like their ancestors while other descendants became quite different one guess is that Keen vision and excellent muscular control were useful for quick movements high in the trees since complex movements are related to a larger brain life in the trees might have favored those animals with larger brains and what about the evolution of hands again it may have been that more flexible Paws Paws that could could grasp a branch or other object were an advantage in the trees and again these more complex movements would be related to a larger brain but whatever The evolutionary pressures were a long series of genetic changes and natural selection did result in fingers that could be drawn together on some of these early primates by being able to lift food to the mouth the animal could keep its head erect and see approaching enemies at the same time Generations passed and still more changes occurred there were animals with eyes closer to the front of the face and full threedimensional vision became possible when primates like the maret developed with eyes in front of the head the changes that occurred were subjected to the ultimate tests of natural selection were they in advantage to the animal's survival and did the animal produce Offspring with these new genetic combinations other changes appeared there were primates with fingers and hands capable of more and more complex motions but though the capabilities were there the animals were still using these for Paws mostly for Locomotion with some of the tree dwellers the hands and arms provided the principal means of movement even when some primates had ventured from the trees to the ground the arms were still just another set of legs but with this all important difference even though the hands were used to support the animal they were capable of other things as well in time some of the primates were using the for Paws less and less for support and Locomotion and here was another step in the evolution of man as the hands were partially freed from their supportive job they were able to try other things like holding a stick the step from this to Tool making may have taken hundreds or thousands of generations and no one knows precisely where to say the line between near man and man was actually crossed perhaps it was after they had learned to make tools and had begun using fire or did it happen after the development of speech and where did it happen did true man first appear in South Africa and then did he multiply and spread to North Africa and then East to Asia or during the long process of evolution did man emerge in South Africa and Asia at the same time or somewhere in between and after true man did appear how and when did groups of them become so separated from one another that any new changes that took place couldn't be shared between the different groups and was it in this isolation that the different races of humans emerged no one is sure just when the different colored skins or the special folds around the eyes appeared but the separation was apparently never long enough or complete enough for different species of men to evolve today genetic changes are still taking place but in which directions are they changing man perhaps the men of the future will be those whose minds and bodies can best withstand the stresses of an increasingly crowded world and perhaps as man continues learning how to control his environment he will also learn how to control his own evolutionary destiny [Music]