An international group of scientists found out when there was a division of Homo sapiens into separate groups. This process, which led to the emergence of modern genetic diversity and races such as Mongoloids, Negroids and Capoids, began more than 260 thousand years ago. "Lenta.ru" tells about the research, the preprint of which is published in the bioRxiv repository.
According to archaeological, paleontological and genetic data, the evolution of modern humans (Homo sapiens) took place in Africa, south of the Sahara. In the region of the East African Rift Valley, which stretches from Ethiopia to Mozambique, the oldest remains of people of the genus Homo were found, belonging to the Olduvai culture (2.7-1 million years ago), characterized by the most primitive stone tools. In 1960, the remains of a skilled man (Homo habilis) were discovered here, which led to the emergence of a hypothesis about the African origin of man.
The oldest human fossils of the modern anatomical type have also been found in East Africa. The age of the fossilized bones is estimated at 195 thousand years. At the same time, the results of genomic studies have shown that the hunter-gatherer peoples living in South Africa are carriers of the oldest DNA. These include representatives of the capoid (Khoisan) race - for example, the Bushmen. The separation of the Khoisan peoples from the rest of humanity took place, according to researchers, about 160-100 thousand years ago.
The Bushmen are a vivid illustration of the fact that there are no outward signs characteristic of only one human race. They have dark skin with a reddish tint, but anthropologically they differ from Negroids: they are relatively short (up to 150 centimeters), and their faces have Mongoloid features. Bushmen are genetically most different from other groups of people now existing.
Border Cave. Photo: Androstachys / Wikipedia
Koisan peoples have haplogroup A - a specific set of DNA on the Y chromosome, inherited from one ancestor. It was Y-chromosomal Adam - the ancestor of all living people. According to the latest estimates, he lived about 200-300 thousand years ago. He has nothing to do with the biblical Adam, since he was not the first person in the world - his parents were also people. A closely related concept is Mitochondrial Eve, from which modern mankind inherited mitochondrial DNA.
Traces of the ancestors of the Bushmen were found in the Sibudu Cave, Border Cave and other places in KwaZulu-Natal - the province of South Africa. Here the age of the oldest human settlements reaches 100 thousand years.
Researchers from Sweden and South Africa analyzed DNA extracted from seven individuals who lived in the past two thousand years. Remains of these people have been found in the area of Ballito Bay and Doonside, Champagne Castle and elsewhere. Scientists have established the sequence of nucleotides in the DNA of three hunter-gatherers who lived two thousand years ago, which are characterized by the culture of the Stone Age, and four farmers of the Iron Age culture (0.5-0.3 thousand years ago).
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Although the concepts of "Stone Age" and "Iron Age" refer to specific cultural and historical periods in the development of mankind, in different parts of the world they began and ended in different centuries. Thus, some African tribes used stone tools until European colonization. In South Africa, the Stone Age passed immediately into the Iron Age, although in Europe it first went over to the Bronze Age.
Bushman children from Namibia. Photo: Nicolas M. Perrault / Wikipedia
The results of genomic analysis showed that all three hunter-gatherers and one farmer were carriers of the mitochondrial haplogroup L0d, which is found in modern representatives of the capoid race. The remaining three representatives of the Iron Age culture had the mitochondrial haplogroup L3e, characteristic of the Bantu speakers (these peoples live almost throughout Africa, south of the Sahara).
Scientists have also assessed the level of relationship between the genomes of ancient people and modern peoples. To do this, they compared the genetic data of seven individuals from KwaZulu-Natal with databases of genotypes from South Africa, the entire African continent and other regions of the globe. The results were consistent with previous ones: the hunter-gatherers were related to the capoid race, and the Iron Age farmers were from the Bantu native populations of South Africa.
The researchers noticed that the genomes of Bushmen and other Khoisan peoples living in Africa at the moment showed signs of mixing with migrants from Eurasia and East Africa, such as Amhara, Ethiopia's second largest people. The degree of crossbreeding among the Khoisan reaches 9-22 percent. This mixing took place, according to scientists, 1.5-1.3 thousand years ago.
Anthropologists were also able to uncover some details of early human history. The relatively well-preserved genome of the boy from Ballito Bay came in handy for this. Its DNA remained intact by genetic confusion, allowing scientists to assess the degree of divergence between hunter-gatherers from KwaZulu-Natal and other peoples. To do this, the boy's DNA and 12 other genomes belonging to archaic and modern people were compared. According to the results obtained, the ancestors of the Khoisan peoples separated from the rest of Homo sapiens 285-365 thousand years ago.
Previously, it was believed that the earliest division of Homo sapiens into separate groups occurred approximately 160-100 thousand years ago. The new dating is almost half of the time that has passed since the Neanderthals (Homo neanderthalensis) and Denisovans (Homo denisova) separated from the main branch of Homo 700-765 thousand years ago. According to the researchers, H. neanderthalensis and H. denisova diverged from each other almost simultaneously with the division of H. sapiens into groups.
Thus, the results obtained by scientists postpone the beginning of the process of dividing humanity into races by almost 100-200 thousand years. This happened before H. sapiens left Africa (one hundred thousand years ago), moving to the Middle East and Europe.
Alexander Enikeev
