Scientists have identified 5 episodes of the migration of ancient people from Africa to Arabia. According to the results of an international study published in the journal Nature, the first people came to Arabia from Africa 400 thousand years ago. After that, there were at least four more waves of migration, each of which coincided with a short period of decreasing aridity in the region, when the Arabian Peninsula was covered with greenery and numerous lakes. Archaeological excavations have been conducted on the territory of Saudi Arabia for a long time, but until now they were limited to coastal areas and small oases, and the vast interior remained unexplored.
Also, archaeologists from the Max Planck Institute for the History of Mankind in Jena (Germany), together with colleagues from other countries and with the support of the Ministry of Culture of Saudi Arabia, carried out work on the Hall-Amaishan 4 site and in the Jubba oasis in the Nefud desert in the north of the Arabian Peninsula and found thousands of stone tools and animal bones, indicating repeated stay in this area of ancient people.
Geographically, the finds are confined to the coastal zone of a large lake, once located between two large dunes. The researchers identified six periods of fullness of the lake, with five of which the finds of artifacts coincide in time.
The results of geochronological analyses of stone tools showed that people lived here about 400, 300, 200, 100 and 55 thousand years ago. The authors determined the age of the finds by the method of luminescent dating, which records the time during which tiny grains of sand on the surface of artifacts were exposed to sunlight.
The authors note that each of the five phases of human stay on the shores of the lake in the Nefud desert is characterized by its own type of material culture – from the Acheulean culture of the "hand axe" of the Lower Paleolithic to the Middle Paleolithic technologies of stone flakes – by which it is possible to trace the change in human culture over time.
In some cases, the differences in material culture are so great that, according to researchers, this indicates the simultaneous presence in the region of various groups, and possibly species of hominins who came to Arabia, both from Africa and Eurasia. This is confirmed by animal fossils. Most of them are of African origin, but there are also those who came from the north.
The discovery of large mammal fossils in the middle of this hyper—arid desert is a unique event. The most remarkable was the discovery of several fragments of hippo bones. Currently, their habitat is limited to humid areas of Africa, and their presence in the Nefud desert over the past 400 thousand years is a convincing proof that the Arabian Peninsula was much wetter in the past than it is today, against the general background of the arid climate on the peninsula, phases of increasing precipitation periodically occurred, which led to the formation of thousands of lakes, rivers and swamps. At that time, favorable conditions for the migration of people and animals were established in the region. Arabia has become a kind of migration hub, one of the meanings of the English word hub is the center of attention, interest, activity.