Africa, the planets 2nd largest continent and the second most-populous continent (after Asia) includes (54) individual countries, and Western Sahara, a member state of the African Union whose statehood is disputed by Morocco. The continent is bounded on the west by the Atlantic Ocean, on the north by the Mediterranean Sea, on the east by the Red Sea and the Indian Ocean, and on the south by the mingling waters of the Atlantic and Indian oceans.
As for Africa, scientists have formerly concluded that it is the birthplace of mankind, as large numbers of human-like fossils (discovered no where else) were found on the continent, some dating back 3.5 million years.
Africas total land area is approximately 11,724,000 square miles (30,365,000 square km), and the continent measures about 5,000 miles (8,000 km) from north to south and about 4,600 miles (7,400 km) from east to west. Its northern extremity is Al-Ghīrān Point, near Al-Abyaḍ Point (Cape Blanc), Tunisia; its southern extremity is Cape Agulhas, South Africa; its farthest point east is Xaafuun (Hafun) Point, near Cape Gwardafuy (Guardafui), Somalia; and its western extremity is Almadi Point (Pointe des Almadies), on Cape Verde (Cap Vert), Senegal. In the northeast, Africa was joined to Asia by the Sinai Peninsula until the construction of the Suez Canal. Paradoxically, the coastline of Africa—18,950 miles (30,500 km) in length—is shorter than that of Europe, because there are few inlets and few large bays or gulfs.
Africa has an array of diverse ecosystems, from sandy deserts to lush rain forests. Two of Africas most interesting geographical features are the Nile River System, the worlds longest, and the massive Sahara Desert, the worlds largest.
Africa contains an enormous wealth of mineral resources, including some of the worlds largest reserves of fossil fuels, metallic ores, and gems and precious metals. This richness is matched by a great diversity of biological resources that includes the intensely lush equatorial rainforests of Central Africa and the world-famous populations of wildlife of the eastern and southern portions of the continent. Although agriculture (primarily subsistence) still dominates the economies of many African countries, the exploitation of these resources became the most significant economic activity in Africa in the 20th century.
Climatic and other factors have exerted considerable influence on the patterns of human settlement in Africa. While some areas appear to have been inhabited more or less continuously since the dawn of humanity, enormous regions—notably the desert areas of northern and southwestern Africa—have been largely unoccupied for prolonged periods of time. Thus, although Africa is the second largest continent, it contains only about 10 percent of the worlds population and can be said to be underpopulated. In general, the peoples of northern Africa adhere predominantly to Islam and those in Southern Africa largely to Christianity, although their distributions are not discrete.
Africa is the most tropical of all the continents; some four-fifths of its territory rests between the Tropics of Cancer and Capricorn. As a consequence, the cultures and the physical variations of the peoples reflect adaptation to both hot, dry climates and hot, wet climates. Dark skin is the dominant characteristic of indigenous African peoples, but skin colour is not uniform. Skin colour shows a clinal variation from a light or tan colour in the northern fringe of the continent, which has a Mediterranean climate, to very dark skin in certain Sudanic regions in western and East Africa, where radiation from the Sun has been most intense. Africa has the most physically varied populations in the world, from the tallest peoples to the shortest; body form and facial and other morphological features also vary widely. It is the continent with the greatest human genetic variation, reflecting its evolutionary role as the source of all human DNA.
Although the precise number is unknown, there are several thousand different societies or ethnic groups in Africa. They are identified by their recognition of a common culture, language, religion, and history. But in some areas the boundaries among ethnic groups and communities (villages, towns, farm areas) may not always be clear to the outsider. Most Africans speak more than one language, and frequent migrations and interactions, including intermarriage, with other peoples have often blurred ethnic distinctions. There are an estimated 900 to 1,500 different languages, but many distinct political units share a common or similar language (as among the Yoruba, Hausa, and Swahili-speaking peoples).