According to an international study published in the journal Nature, the first humans came to Arabia from Africa 400,000 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 in Saudi Arabia for a long time, but until now they have been limited to coastal areas and small oases, and the vast interior has remained unexplored.
Recently, archaeologists from the Max Planck Institute for the History of Humanity in Jena, Germany, along with colleagues from other countries and with the support of the Ministry of Culture of Saudi Arabia, carried out work at the Hall Amayshan 4 site and in the Jubba oasis in the Nefud desert in the north of the Arabian Peninsula and discovered thousands of stone tools and animal bones, testifying to the repeated stay of ancient people in this area.
Geographically, the finds are confined to the coastal zone of a large lake, once located between two large dunes. Researchers have identified six periods of high water flow in the lake, with five of which the finds of artifacts coincide in time.
The results of geochronological analyzes of stone tools showed that people lived here approximately 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 the artifacts were exposed to sunlight.
The authors note that each of the five phases of a person's stay on the shores of a lake in the Nefud desert is characterized by its own type of material culture - from the Acheulean “hand ax” culture of the Lower Paleolithic to the Middle Paleolithic technologies of stone flakes, which can be used to track the change in human culture over time.
In some cases, the differences in material culture are so great that, according to the researchers, this indicates the simultaneous presence in the region of various groups, and possibly species of hominins who came to Arabia from both Africa and Eurasia. This is confirmed by the fossils of animals. Most of them are of African origin, but there are some that came from the north.
"The discovery of fossils of large mammals in the middle of this hyperarid desert is a unique event," said co-author Julien Louys, associate professor at the Australian Research Center for Human Evolution, in a press release from Griffith University. "They are currently confined to the humid regions of Africa, and their presence in the Nefud Desert over the past 400,000 years is compelling evidence that the Arabian Peninsula was much wetter in the past than it is today."
According to the authors, against the general background of the arid climate on the peninsula, phases of increased precipitation periodically occurred, which led to the formation of thousands of lakes, rivers and swamps. At this time, favorable conditions for the migration of people and animals were established in the region.