◊ The earliest human migrations out of Africa occurred through the Middle East, namely over the Levantine corridor, with the pre-modern Homo erectus about 1.8 million years BP. One of the potential routes for early human migrations toward southern and eastern Asia is Iran.
Haplogroup J-P209, the most common human Y-chromosome DNA haplogroup in the Middle East today, is believed to have arisen in the region 31,700±12,800 years ago. The two main current subgroups, J-M267 and J-M172, which now comprise between them almost all of the population of the haplogroup, are both believed to have arisen very early, at least 10,000 years ago. Nonetheless, Y-chromosomes F-M89* and IJ-M429* were reported to have been observed in the Iranian plateau.
There is evidence of rock carvings along the Nile terraces and in desert oases. In the 10th millennium BC, a culture of hunter-gatherers and fishermen was replaced by a grain-grinding culture. Climate changes and/or overgrazing around 6000 BC began to desiccate the pastoral lands of Egypt, forming the Sahara. Early tribal peoples migrated to the Nile River, where they developed a settled agricultural economy and more centralized society.