ORIGIN AND EVOLUTION OF MAN
Since in the first decades of the nineteenth century geologists came to the conclusion that the earth was formed through very slow and continuous processes, during extraordinarily long periods, paleontologists began to speculate with the idea that the fossilized remains of animals that they had been meeting for centuries had to have a much greater antiquity than hitherto attributed to them.
Other sciences, such as physics and chemistry, provided increasingly reliable procedures to date the findings of paleontologists, and when the origin of Darwin's species was published in 1859, the foundations were laid for the triumph of evolutionary theory, according to which current living beings -including man- are the result of the evolution of previous species.
Evolution of hominid species: Proconsul, Plioplithecus, Australopithecus, Homo habilis, Homo erectus, Neanderthal, Homo sapiens. The Proconsul is considered as the first common ancestor between the monkey and the man, but the Australopithecus afarensis is considered as the first ancestor of the Homo sapien
The first hominid
Man made his appearance on earth about three or four million years ago, in some African forest. The oldest ancestor found so far common between man and monkey is called Proconsul (about 18 million years ago), has a small brain and four short joints adapted to life in trees. The next step is called Ramapithecus (14 million years ago) which is considered the first hominid. But the affinity of the African remains (Keniapithecus) with the gorillas, and of the Asiatics (Sivapithecus) with the orangutans, has established the thesis that it is a common ancestor.
Then, the Plioplithecus was a genus of different species of catarrhine primates (with characteristic nasal orifices open downwards, separated by a thin nasal septum) that lived approximately 17 million years ago, and up to 11.5 million years ago.
Australopithecus
From this moment a gap of almost 10 million years between the Ramapithecus and the first known ancestor of man, so to speak, the Australopithecus afarensis.
A series of hominid remains have been found for this period but they would not yet be considered a direct ancestor of man. Among them I would highlight the Ardipithecus Ramidus (= root), discovered in Ethiopia in 1992, it is a biped, similar to a chimpanzee, who lived about 4.4 million years ago and had to stand up thanks to the droughts that occurred in the jungles They transformed them into sheets that forced them to stand up and walk on their two legs. Australopithecus anamensis, a very primitive hominid with wider molars and thicker enamel, also stands out.
image source
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Cover of the work "The Origin of Species" by Charles Darwin, published in 1859.
In 1974, Austrapithecus afarensis appeared in Ethiopia (it lived about 3.9 to 4 million years ago), specifically in a region in northwestern Ethiopia called Afar. This specimen was known as "Lucy", and this species is considered as the first ancestor of man. It was a female skeleton complete by 40%, although the first remains of an Australopithecus had previously been found in South Africa in 1924, but it was only a baby skull. "Lucy" was the oldest specimen of this species that would live in East Africa, weighed 30 to 50 kilos in weight, upright and were able to turn their hands. At the same time, they were distinguished by the development of their strongest jaws and dentures.
Australopithecus bahrelghazali was the only specimen found outside East Africa (it lived about 3.58 million years ago). It receives its name from the oasis of Bahr-el-Ghazal, in the Republic of Chad, in central Africa. It is considered a species of Australopithecus different from the one that came to evolve towards the genus Homo.
Austrapithecus africanus lived in southern Africa about 2.5 million years ago (even up to 3 million years ago). These species peranecen in vast plains of grass and shrubs, near lakes and rivers. They fed on fruits, seeds and tubers, with the aforementioned exception of the Africanus, who were omnivores. They led a nomadic life, in small groups of several males and females, united by a relationship of collaboration better than that observed in modern monkeys. The youngest A., A. Robustus became extinct being coeval to man.
The Australopithecus garhi: lived about 2.5 million years ago in the area of present-day Ethiopia. He had a remarkable cranial capacity of 450 cm3 and other special facial features.
Finally, Australopithecus sediba lived about 1.78 to 1.95 million years ago in southern Africa. Two partial skeletons were found in the Cradle of Humanity, in South Africa (about 50 kilometers northwest of Johannesburg). This species has characteristics that bring it closer to both the Homo genus and Australopithecus, which is why some paleontologists place it as the most feasible direct ancestor of humans. Either way, it is the most recent species of Australopithecus.
Homo habilis
The next step, Homo Habilis, (2.4 to 1.4 million years ago), its oldest remains, an upper jaw, was found in Ethiopia in 1996, also known to have been found next to stone tools the same time. It seems that the manual ability was fundamental in adapting to the new times, a period of progressive cooling that would end in droughts and lack of food, which would lead to these to maintain a hard struggle for survival. This is the time when utensils begin to appear, called primary, is what would translate this manual skill and the difficulty of performing certain functions for the reasons mentioned above.
The first remains of H. Habilis were found in the 1960 by Louis Leakey in Tanzania. They were attributed to this species because of their manual abilities and brain mass, one third larger than Australopithecus. This species would begin to be omnivorous, collect the remains left by the hunter animals, and also keep the bone marrow, as well as being able to collect herbs, fruits, eggs and catch small animals.
Homo erectus
The second to last step was the Homo Erectus (about 1, 6 million to 200,000 years ago), had a cranial capacity of 900 cc, dominated the fire and used it, had a rough face and pronounced incisors. This domain of fire would allow it, among many other things, to better withstand the low temperatures of the glacial period and to be able to spread more easily due to its better adaptation to each environment. At the same time, there is a greater development of the utensils that are still made of stone, it is the time of expansion in Europe and Asia.
Homo sapiens
The penultimate step towards evolution will be Homo Sapiens whose oldest remains date back around 195,000 years ago. One of the best-known subspecies is the Neanderthal man or Homo sapiens neanderthalensis (between 75,000 to 36,000 years). They were hunters, they came to dominate the fire fully and with a great improvement in the tools they used, as well as the development of hunting instruments (spear, bow, arrows, ...). Also belong to this period the first artistic manisfestacoiones of a utilitarian nature.
Finally, the modern or anatomically modern human man (Homo sapiens sapiens) evolved from other species of Homo sapiens around 195 million years ago (men from Kibish - discovered in 1967 in the valley of the Omo River, southern Ethiopia), with a cranial capacity of 1400 cc and a highly developed cerebral cortex, which will lose body hair over time, as well as reduce the size of the jaws and dentition. One of the greatest qualitative leaps of this species would become (much later) the development of speech, as well as language and writing.
The Neanderthal man lived with the first modern men (Cro-Magnon man) in Europe, and in fact could have competed for resources and food sources before his disappearance some 39,000 to 41,000 years ago, approximately 5,000 years after modern man appeared In the continent.