The modern story of human evolution started with the ice breaking theory by Charles Darwin The origin Of Species, the first scientific concept that put forward descendence of Homo sapiens from the Ape like animals of order primates. Darwin in his another book The Descent of Man in 1871, put forward the idea of human evolution from Ape-like primates.
In early Oligocene period the Homo line started developing and branched off from Ape line, however the rate of growth was very much slow and complex. Such slow and complex process lead to the existence of humans on the surface of earth. One can't part ways from the fact that the evolutionary process among us is continuing during contemporary period too.
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The first line among modern day apes that differentiated were Gibbon which evolved through an intermediate stage Pliopithecus in early poliocene bed in GERMANY. Followed by the division of remaining Ape-men stock. Among remaining ones the first to diffentiate was Orangutan line, followed by chimpanzees and the last to diffentiate was guerilla line in Miocene period.
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Thus the Miocene period witnessed the split of Homo line from Ape line. In the middle of the Miocene the common ancestors like proconsul split into the modern day apes and first homonoid like Australopithecus. Australopithecus is considered the first fossil of human evolution. Australopithecus witnessed considerable external and internal bodily changes to adopt itself in climatic and dietetic situations.
Africa the cradle of human evolution.
The story of human evolution we know today that evolution of mankind happened in Africa was not same a century back. Though Charles Darwin in his book, The Descent of man 1871, wrote human evolution started in African continent but he used the word probable and cited his reason the presence of apes in the same continent. After his prediction for about 50 years no scientist had to accepted it because of discoveries of JAVA MAN and other homonoid fossils in Euro-asian region.
What changed the scientists to visit this dark continent was a fossil discovery in South Africa in 1924. Raymond Dart was the first Anthropologist who discovered fossil evidences of a child (he himself called it the parent of all mankind!!! ) now we know as Taung Child(Australopithecus Africanus). In his book "Adventures With Missing Link" Dart wrote about his discovery later. Darts work opened the gates for Archeological Anthropologists in Africa and was followed by the river of Anthropologists. In 1935 Robert broom in Sterfontein found the Ape-like man, in 1938 a student Gert Treblanche handed over the skull fossil to Dart which was later named Parananthropus robustus, L. S. B Leaky and Mary Leaky discovered Australopithecus boisei near Olduvai in 1959. Since than hundreds of humanid fossils or evidences of human fossils were recovered from African continent. All earlier ancestors of human fossils records were discovered from Africa that makes it unique and is considered the Cradle for Human Evolution.
Introductory summery of human evolution
The series of events in human evolution started in pliocene period with the emergence of Homo species and first one was AUSTRALOPITHECUS. Many species of Australopithecus, who's fossils were collected since 1924 to today's time are Australopithecus afaricuns, A. afarances, A. boisei. But all the three species met with blunt end while the A. Afarances is believed to be predecessor of Homo Habilis.
Homo Habilisis the first species of directly associated with the modern day humans. Being the first species of Homo genra, Homo Habilis could stand erect though the steeping was not like the modern day man(Homo sapiens). Richard Leaky discovered the fossils hominids in Rodolfo Lake similar to Australopithecus Africans but the brain case was larger in extant and was later named Homo Habilis. The next stage in human evolution through Homo Habilis was Homo erectus.
Homo erectus (pathecanthropus erectus) was largely confined in the old world during the bigning of second interglacial period between two lake to three lake years back, lived in open grass lands in Africa and other climatic regions like cold tundra in Europe to dense forests in Asia. Homo erectus as the name suggests was bipedal (walking on two legs) with erect posture than its predecessor, more cranial capacity and adopted to different climatic conditions. This was the first Homo species that migrated to different parts of the world and didn't confine itself to Afro-europian region. Between 0.3 to 0.2 million years ago spread its progeny from South Africa to Jawa in South East Asia. Culturally Homo Neanderthals are considered the makers of later Paleolithic period of middle pleistocene period between 2 lakh and 3 lakh years ago. Important features of their cultural contribution includes; *use of fire, dwelling shelters, food gathering, hunting, ritual activity, sexual behavior besides the cannibalism. The later feature has controversial evidences but the skull with enlarged foramen magnum found in some skeletons in China, the enlargement could have been done to extract the brain tissue for food or other ritualistic behavior. Homo erectus evolved from Homo habilis around 1,00,000 to three lakh years ago. Homo Neanderthal followed Homo erectus.
Homo Neanderthals dominated earth from 100000 - 35000 years back. Lived in North Africa, Europe, near east and some parts of Asia.
Hooton has classified Neanderthals into progressive and classical forms on the basis of there location and anotomical features.
This Homo species was more closer to humans than any of their predecessor species. Having more cranial capacity, being more culturally advanced and more social.
Cave paintings, cave dwelling, winter clothing, bear cult and human burials are their main cultural advances besides the progress in stone tools and hunting and food gathering. Language was not perhaps well developed because of poor development of pharynx, important feature suggestive of that they would not have been able to pronounce vowels. Ritualistic burials provide the testimony for some sort of religion.
Though the neanderthal man is not considered the direct ancestor of Homo sapien but has lived with him and has shared around 20 percent of its gene pool with modern man. It is believed both had a commen ancestor between 0. 8 to 0.6 million years ago.
Human evolutionary tree.
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Modern man (Homo sapien) The modern day living human species is a sub species of Homo sapien called Homo sapien sapien. The evolutionary history between Homo neanderthaloids and modern man is filled with certain transitional forms, D. Philbeam called them Archaic human and the three commenly know forms are Rhodesian man (Zambia), Saldanaha man (S. A), Heidelberg man (Germany). This period coincides with second interglacial and third glacial period and shared features of both Homo erectus and Homo sapien.
Modern man'sfossils evidences were discovered from different locations of the world the important ones are Cromagnon man from France, Grimalde man from Italy and Chancelade in France.
Cromagnon skull of Old Cromagnon man
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One important feature of Cromagnon man to be noted is that he witnessed the cranial capacity more than that of modern human beings.
The present day humans (Homo sapien sapien) are believed only 10000 years old and is highly intelligent and culturally social among all his predecessors. Human have started to live by modifying its environment for his convenience. The modification of nature leads to the adoptability to any sort of environment which in tern decreases the body to compel for change, the reason to slow down the further process of evolution, though evolution continues but the speed may impede with time.
SOURCES OF CONTENT
- Aiello- Leslie: Dean, Christopher, 1990.
An Introduction to Human Evolutionary Anatomy.London. - Evolution of man wikipedia
- Sabin I, Mr. R, Man's Ebolution(Bombay), 1951
- Shutler, Richard, Early man in New York, 1921.
- Dobzhansky, T., Mankind Evolving, (NewHqven:Yale University press, 1962
- Darwin, Charles, The origin of species and descent of man(New York :D. Appleton & Co.) 1880.
- https://www.smithsonianmag.com/science-nature/how-africa-became-the-cradle-of-humankind-108875040/