Sub-Saharan

Sub-Saharan Africa is, geographically, the area of the continent of Africa that lies south of the Sahara. According to the UN, it consists of all African countries that are fully or partially located south of the Sahara. It contrasts with North Africa, whose territories are part of the League of Arab states within the Arab world. Somalia, Djibouti, Comoros and Mauritania are geographically in Sub-Saharan Africa, but are likewise Arab states and part of the Arab world.

The Sahel is the transitional zone between the Sahara and the tropical savanna (the Sudan region) and forest-savanna mosaic to the south.

Since probably 3500 BCE, the Saharan and Sub-Saharan regions of Africa have been separated by the extremely harsh climate of the sparsely populated Sahara, forming an effective barrier interrupted by only the Nile in Sudan, though the Nile was blocked by the river's cataracts. The Sahara pump theory explains how flora and fauna (including Homo sapiens) left Africa to penetrate the Middle East and beyond. African pluvial periods are associated with a "wet Sahara" phase during which larger lakes and more rivers existed.

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