West Africa West Africa West Africa is the westernmost region of Africa. West Africa has been defined as including 17 countries: Benin, Burkina Faso, the island nation of Cape Verde, Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Mauritania, Niger, Nigeria, the islands of Saint Helena, Ascension and Tristan da Cunha, Senegal, Sierra Leone and Togo. The population of West Africa is estimated at about /1e6 round 0 million people as of . Studies of human mitochondrial DNA suggest that all humans share common ancestors from Africa, originated in the southwestern regions near the coastal border of Namibia and Angola at the
West Africa various ethnic groups. For historical reasons, Western European languages such as French, English and Portuguese predominate in Southern and Coastal subregions, whilst Arabic spreads inland northwards. The Economic Community of West African States (ECOWAS), founded by the 1975 Treaty of Lagos, is an organization of West African states which aims to promote the region's economy. The West African Monetary Union (or UEMOA from its name in French, "Union économique et monétaire ouest-africaine") is limited to the eight, mostly Francophone countries that employ the CFA franc as their common currency. The Liptako-Gourma Authority of Mali, Niger, and Burkina Faso seeks to