13,000 years ago, Europe and Africa underwent an environmental change that would drastically change history forever. The soil which the Africans stood upon became increasingly superior to its European counterpart. Also, an event that is still being debated today took place; the rocks and minerals of Africa began to grow in abundance, also unlike its European counterpart. This allowed African people, especially people in the north, to improve their agricultural strength.
In OTL this is what happened to the Europeans; a single event that allowed their agricultural base to grow and expand, which was followed by population growth, followed by scientific growth. Such an event never happened for the Africans but in this ATL, the Africans, not the Europeans, received this event, drastically changing the future.