This story is based on the idea that sometime after the evolution of humanity, the area at Braasville (the orange dot on the above map) becomes blocked by a minor volcano. The lava and water mix to create a large dam reaching several hundred feet. The Congo basin would be endoheric (no exit to the sea) aside from three spots: the aforementioned exit at Braasville; another at the Oogue river; and a third through the Chari river into Lake Chad. Blocking Braasville would create a large lake, Lake Congo, which would then drain westwards through the Oogue and through the Chari into Lake Chad.
Around 120000BC: a meteor hits the area around modern day Braasville (the orange dot in the picture).
A hot spot forms around modern day Braasville. A series of large scale earthquakes causes lava to break through, which begins to interact with the water from the congo river. A dam starts to form as a result of this interaction.
100000BC: Humanity exits Kenya. They split into three groups, the first heads west into the Congo river basin, the second heads North along the nile river and the third heads South along the Great Lakes.
By 90000BC, the Congo river has been blocked off from the West Coast. The Congo river fills up to form a giant lake that fills up most of OTL DRC.
The humans living in the Congo river basin spread outwards as the Congo lake swells in size. They split once again into two more groups, one which heads north into the Sahel through Sudan, and the other which heads up towards Lake Chad.
By 75000BC, the Congo river overflows in two locations, first, out through the Oogue River into the Atlantic, second, out through the Chari river into Lake Chad. Lake Chad swells to a large size though it doesn't reach it's zenith yet.
Lake Makgadikgadi in OTL Botswana has reached it's largest size. Tribes travelling from the insect ridden Great Lakes area begin to settle around that area.
60000BC: Humans are now present in all of mainland Asia and are beginning to enter Western Europe.
50000BC: Lake Chad has swelled to full size and overflows southwest, connecting with the Niger river before emptying out towards the Atlantic. The tribes around Lake Chad take advantage of the swelling fish population.
40000BC: The Twin Seas cause greater rainfall North of Lake Chad and South of Lake Congo. Near permanent (though greatly varying in size) lakes appear in OTL Sahel and parts of OTL Sahara, and the area of OTL Botswana, Zambia, Zimbabwe and Northern South Africa becomes a large savannah style ecosystem.
Humans are now populous throughout Africa, apart from the North African coast, throughout the middle east, throughout Western Europe, they have reached several of the Asian islands and Australia.
(Note- yes, I know that the way that the blockage of Braasville occurs is highly implausible. Get over it.)
The African Plains
40000BC:
The Kasiyawa (OTL Sahel) and the Kalahari)
In the northern and central Kaciyawa regions, the tribes follow a Nomadic lifestyle, following large herds of oryx's, antelope, gazelle and hartebeast as they travel from lake to lake.
Immediately south of the Kaciyawa is the savannah-forest mosaic, which includes Lake Chad. The marshes, rivers and lakes form pockets of woodland, separated by large fields of grass and brush. There are permanent human settlements, which have begun domesticating dogs and guinea fowl. Around the lakes and rivers, spear fishing is a major source of food.
The tribes here have begun using Calabash fruits to store water, and as a source of food.
The Kalahari ecosystem is dominated by two lakes, the largest, Lake Makgadikgadi which spans some 80000km and is fed by the Zambezi and Cubango rivers and lake Ngami, which is also fed by the Cubango river via an affluent and spans some 80 miles. The third major body of water is the Limpopo river to the south.
There are three major groups of people, those who live in the Cubango system to the East, those who live in the Zambezi system to the East and North, and those who live near the Limpopo to the South.
Tribes there live in permanent settlements, leaving their huts each morning to hunt game nearby. Because they bring their food back to the hut, the first tame dogs in Southern Africa appear here, as the African Wild Dogs gather round to eat the discarded bones.
Fishing is more common in the north, near Lake Makgadikgadi, where the waters are more stable. The rivers that feed into lake Ngami are quite violent, making fishing a risky proposition. The same is true in the Limpopo river.
Agriculture is nearly non-existent, use of plants has begun. Like in Western Africa, the Calabash is prized for it's usefulness in storing and transporting water while hunting, the watermelon and horned melon are regularly sought out and eaten, the seeds of both , grow closer and closer to the villages each year. The same is true of sorghum and some tree fruits such as strychnos spinosa.
