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INTRODUCTION
The evolution of the anthropides i.e. the ancestors of the human kind has been searched very deep in time.
In 2002, in Chad, a skull was discovered, that belonged, according to the French researcher Michel Brunette, to the oldest known member of the evolutionary line that the human kind gave.
It was called Toumai or Sahelanthropus tshadensis, and, it seems that, it walked on his two feet seven million years ago, something disputed by several scientists, though (see design).
The first anthropides in Africa, the Australopithecus (= southern ape) appeared 4.000.000 years ago. The kinds cited below, appeared approximately 2 – 1,5 million years ago and were called human, due to their specific characteristics, such as dipodism (i.e. walking on two feet) the upright position, the ability to make tools, etc.
HOMO HABILIS
Homo habilis who lived in Africa 1,9 million years ago, was the first kind that could walk in an erect position.
It is an early member of the human kind and looked like the Australopithecus, but with human facial features and denture.
HOMO ERECTUS
It is the most evolved figure of Homo habilis, who was replaced 1,6 million years ago and this has been proved by its skeletal elements, as well as its way of life. His oldest name was ape-man the mute and this was so because scientists in the 19th century had imagined him as the link between the humans and the ape. Later, other links were discovered. He lived 1.600.000 to 400.000 years ago and the oldest samples were found in Africa, his first cradle, from where he immigrated following the Nile. He arrived in Java 1.000.000 years ago and in Europe 300.000 years ago. The first Homo erectus was discovered in 1891 in the village Trinil in Java.
Later several fossils of this kind were found. Among these the most well-known is the Sinanthropus peknensis with a brain capacity of 1000 cm3 and many advanced abilities. Homo erectus used fire, which was also used for defense (means of protection), as well as a means of hunting. He even used clothes and made houses. The rational use of his hands in making tools, a clearly human quality, sharpened his mind and his abilities.
Homo erectus was omnivorous, though he was mostly herbivorous than carnivorous. His erect position had positive effects (making of better tools, increase of his brain capacity as a result of his frequent use of his hands, widening of his thorax, etc.), as well as negative ones (less possibilities of escape, appearance of flatfoot, distress of vertebra, difficulties in giving birth and problems in blood circulation, as the heart is burdened by pumping).
HOMO NEANDERTHALENSIS
Homo neanderthalensis is considered to be our first cousin, because he was the first kind of sapiens. He was the evolution of Homo erectus who appeared 400.000 years ago, while the appearance of Homo Neanderthal occurred 130.000 ago and he existed till 35.000 years ago. His name is due to the valley Neader where a fossil was found in 1856. Of course, other similar fossils have been found.
Homo neanderthalensis, however, was not the connective link between Homo erectus and Homo sapiens, because his characteristics are the same with Homo sapiens and it is possible that many of his genes also existed in Homo sapiens sapiens. He lived with his family that was united and organized. He had big jaws, large eye sockets, big cranium lumps (cheekbones, occipital, etc.), a brain capacity of 1600 cm3, strong joints, a face with angles and was stronger than Homo sapiens sapiens.
He could live in cold climates, due to his thick hairiness and he used fire effectively. His nostrils were defective, because although he lived in cold climates, they were big. Maybe his disappearance was due to this defect. It is speculated that females gestated for 11 months. He distinguishes from modern human from the particular structure of his head. He had a huge brain capacity – bigger than that of today’s human – and lacked in volume in the sincipital lobes, where the prekinetic centers that control the superior mental functions are located.
Therefore, he was of lower mental ability in comparison with today’s human. It is believed that Homo neanderthalensis and contemporary human lived simultaneously for some period of time, but, in competition. He had not spread to many places, a sign of his non-adaptability and the small duration of his existence. Fossils were found in southern and central Europe and central Asia (Uzbekistan), as well as in south-west Asia.
Fossils have not been found in Africa, America and Eastern Asia. He made tools of stone; he used fire, clothes and participated in various rituals. He buried for the first time the dead in a sidelong position with bent knees. He probably believed in after death life. This means, of course, that he had religious consciousness. He made rudimentary art, because paintings have been discovered in caves and maybe he used osteal music instruments. He had more developed speech.
Homo neanderthalensis, indeed, may not have contributed to our evolution; however, the progress he achieved in his behavior, thinking and culture is noticeable, a fact that indicates that at his cognate with ours gene reserves, the “expression” of more advanced characteristics had begun, which were perfected in our kind. The so-called Mousterian stone art of the Neanderthal, by which raw material was better exploited for the making of more refined stone tools (scrapers, etc.) was much superior and of a larger complexity in relation to the oldovian stone art of Homo habilis and the Chilean tools of Homo erectus. There is also evidence that he took care of the sick or wounded members of his cluster buried his dead with rituals (fossilized pollen of wild flowers and a circle of horns from rock goats were found in a tomb), he formed abstract thoughts for the process of firestone and carved certain signs on stones, of inscrutable yet importance. The findings that relate to the frequencies with which his ear was coordinated are noticeable, findings that resulted from studies of the size and the shape of the ear ossicles, which convert sounds in acoustic signs to the brain.
The frequencies of our normal speech are 2 – 4 KHz, similar to those of the Neanderthal’s ancestor and Homo Heidelbergensis who had a similar ear function, something that is interpreted as an indication that since then the Homos in question (maybe 500.000 years ago) phonated comprehensive phonetic sounds that could be considered as a first language, a first form of speech. 30.000 years ago, at the most remote areas of Southern Spain and Croatia, the last Neanderthals died, leaving Homo sapiens as the only heir on earth. Neanderthals survived for almost 25.000 years. They endured the most severe climate conditions that the planet has ever known. However, when the time came, as like many other kinds, Neanderthals disappeared. This abrupt disappearance is the subject of many studies. The speculations are many: He disappeared due to the genocide that the Modern Human unleashed. An indication of this, are the massive tombs where there is evidence of forcible deaths. Darwin speculates that the battle between the cognate kinds was very tough. This point of view does not take into consideration that Modern Human was not as muscular as the Neanderthal and consequently it was difficult to eliminate him.
However, Modern human had superior intelligence and managed to dominate.
His large nostrils were maybe the reason he disappeared. The era he lived was interglacial and he could not survive the cold. The large nostril cavity made him often sick. Maybe he was the victim of an expanded epidemic that reduced the population at low levels to disappearance.
In history there have been many epidemics (cholera, plague, etc).
However, if this had been the case, Modern human should have also been affected. Some allegate that Neanderthals exist among us, due to his intermarriage with Modern Human.
Maybe there are many reasons why he disappeared. In other areas because of cold, in others because of his elimination from humans, in others because of his intermarriage and, finally, in others he was the victim of an epidemic disease.
For if Neanderthal is our direct ancestor the reply is negative; and this is because his genetic isolation could not contribute essentially to the evolutionary line of modern humans. Besides, the analysis of the fossils of mitochondrion DNA from the skeleton found at the valley of Neanderthal in comparison with that of modern human shows that the evolutionary line of the Neanderthal and the modern human was cut off a long time ago.
HOMO SAPIENS SAPIENS
He began as a food collector – hunter, however, in a more intellectual level than the previous forms. He dominated earth, after prevailing over his direct competitor, Homo neanderthalensis, in the subject of food and space.
The laws of G. Gause or Grombie are relative, that is, in the same ecosystem two cognate kinds that occupy the same ecologic nest cannot co-exist. Obligatorily, one kind, the more adaptive kind will eliminate the other due to the mechanism of natural choice. A variety of Homo sapiens sapiens is the Cro-Magnon man (he was found, at Cro-Magnon in France).
The cradle of Cro-Magnon man is Africa, from where he immigrated to Europe. His brain capacity was large (1600 cm3), and he was rather high (1,80 – 1,94 m). According to certain anthropologists he did not eliminate immediately the Neanderthal, but he first got into intermarriage and some characteristics of the Neanderthals were produced, something that is discovered in the similarity of the fossils. Such fossils of Homo sapiens sapiens, approximately 100.000 years old, show the same brain size as of today’s human (1.350 – 1.400 cm3) and possibly those humans seemed to think like we do, for example, they used ochre to paint their body, even if the symbolic perception, art and music had not been developed.
Furthermore, he was an active hunter, he had an improved technique and his tools were more advanced – as a result of his brain status.
During his life he met many bad weather conditions – glacier periods. Researches conducted in 2000 by Swedish scientists show that modern human evolved in Africa and from there he started immigrating to other continents approximately 52.000 years, according to specialists, that analyzed the genetic material of mitochondrium of 53 humans of different nationalities.
This theory is called Out of Africa hypothesis and according to this modern human spread on the whole planet starting from the African areas south of Sahara.
CONCLUSION
It is obvious from the above that the human being did not evolve only from the aspect of anatomy in the course of time. In comparison with other primates he is distinguished for the extended abilities to plan and solve problems, use speech, create art, dependend on technology and his large social complexity.
Bibliography and Iconography
David Lambert, The Cambridge Guide to Prehistoric Man, Cambridge University Press, 1987
British Natural History Museum, Man’s Place in Evolution. Cambridge University Press, 1991
Kosmas Touloumis, Prin apo tin Istoria (Before History), Vanias, Thessaloniki 1999
www.becominghuman.org. The Institute of Human Origins. College of Liberal Arts and Sciences. University of Arizona State. Last Update 7 March 2007
www.bbc.co.uk/sn/prehistoric_life/ BBC. Last Update 8 March 2007
DNA and History: The Geographic Project. DVD from National Geographic Channel. National Geographic Society 2006
http://en.wikipedia.org/wiki/Human_evolution, Wikipedia Foundation, Inc, last modified 17 March 2007
