Answer:
While the Sahara is considered the largest desert in the world today, this was not always the case. In the 12-8 Millennium BC, the Sahara was actually a grassland with even rivers and lakes.
This has been proven by many cave drawings found in the area and also through geological surveys.
As such, evidence shows that there were early communities of hunters and gathered living in the area but they eventually developed into more sophisticated societies where cultivation and herding was practiced.
As such, while major neolithic civilizations are mostly associated with the Near East, Sahara also saw major activity around the same time.