African Sheer Zone
Gray areas are interconnected water systems
The evidence of Genesis point to Africa as the point of origin of humans, and the urheimat of Abraham's cattle-herding Proto-Saharan ancestors (Sumerians). The shrine city of Nekhen on the Nile dates to 3500 BC and was an early site of Horite Hebrew worship. It has a twin city on the opposite side of the river.
The aquatic civilization of middle Africa has been the subject of interest after archaeologists have found 9,000 year fish bones, harpoons, and pottery along dried river and lake beds.
Alex Wilshaw describes the changes that took place in middle Africa and along the Mega-Nile Valley.
The Late-Pleistocene/Holocene period was characterised by wet and dry phases (pluvials and interpluvials) that caused a series of associated changes in lake levels; these changes ranged from full lake overflow (when the lakes of Nakuru and Elmenteita formed a single body of water) to complete desiccation, which resulted in an archaeological hiatus between 6.0 and 4.0 thousand years ago (kya). Within the lake basins, there are three different types of ecologies that exist in bands at different altitudinal levels – savannah (lowland), bush-woodland (mid-range) and montane-forest (highland). The climatic changes caused these ecological bands to migrate altitudinally; wet phases led to the expansion of bush and montane-forest into lowland areas, and arid phases saw the expansion of savannah lands to higher altitudes. (From here.)
This video tells the story of how the Sahara sustained life and how it came to be a desert.
Related reading: Climate Change and the Book of Genesis; Water Systems Connected Nile and Central Africa; When the Sahara Was Wet; Sudan is Archaeologically Rich; 70,000 Year Settlement in the Sudan; The Lithic Traditions of Late Pleistocene settlement at Afad, Sudan by Piotr Osypiński; Boats and Cows of the Proto-Saharans; Cemetery Dates to Time Before Noah; African Stone, Shell and Egg Technologies; Why Nekhen is Anthropologically Significant