Africa

Africa is the world's second-largest and second most-populous continent, after Asia. At about 30,221,532 km² (11,668,545 sq mi) including adjacent islands, it covers 6% of the Earth's total surface area, and 20.4% of the total land area.[1] With more than 900 million people (as of 2005)[2] in 61 territories, it accounts for about 14% of the world's human population. The continent is surrounded by the Mediterranean Sea to the north, the Suez Canal and the Red Sea to the northeast, the Indian Ocean to the southeast, and the Atlantic Ocean to the west. There are 46 countries including Madagascar, and 53 including all the island groups.

Africa, particularly central eastern Africa, is widely regarded within the scientific community to be the origin of humans and the Hominidae tree (great apes), as evidenced by the discovery of the earliest hominids and their possible ancestors, as well as later ones that have been dated to around seven million years ago – including Sahelanthropus tchadensis, Australopithecus africanus, A. afarensis, Homo erectus, H. habilis and H. ergaster – with the earliest Homo sapiens (human) found in Ethiopia being dated to ca. 200,000 years ago.[3]

Africa straddles the equator and encompasses numerous climate areas; it is the only continent to stretch from the northern temperate to southern temperate zones.[4] Because of the lack of natural regular precipitation and irrigation as well as glaciers or mountain aquifer systems, there is no natural moderating effect on the climate except near the coasts.


Africa is considered by most paleoanthropologists to be the oldest inhabited territory on Earth, with the human species originating from the continent. During the middle of the twentieth century, anthropologists discovered many fossils and evidence of human occupation perhaps as early as 7 million years ago. Fossil remains of several species of early apelike humans thought to have evolved into modern man, such as Australopithecus afarensis (radiometrically dated to approximately 3.9–3.0 million years BC),[11] Paranthropus boisei (c. 2.3–1.4 million BC)[12] and Homo ergaster (c. 600,000–1.9 million BC) have been discovered.[1]

The Ishango bone, dated to about 25,000 years ago, shows tallies in mathematical notation. Throughout humanity's prehistory, Africa (like all other continents) had no nation states, and was instead inhabited by groups of hunter-gatherers such as the Khoi and San.[13][14][15]

At the end of the Ice Ages, estimated to have been around 10,500 BC, the Sahara had become a green fertile valley again, and its African populations returned from the interior and coastal highlands in Sub-Saharan Africa[citation needed]. However, the warming and drying climate meant that by 5000 BC the Sahara region was becoming increasingly drier. The population trekked out of the Sahara region towards the Nile Valley below the Second Cataract where they made permanent or semi-permanent settlements. A major climatic recession occurred, lessening the heavy and persistent rains in Central and Eastern Africa. Since then dry conditions have prevailed in Eastern Africa, especially in Ethiopia in the last 200 years.

The domestication of cattle in Africa precedes agriculture and seems to have existed alongside hunter-gathering cultures. It is speculated that by 6000 BC cattle were already domesticated in North Africa.[16] In the Sahara-Nile complex, people domesticated many animals including the pack ass, and a small screw horned goat which was common from Algeria to Nubia.

Agriculturally, the first cases of domestication of plants for agricultural purposes occurred in the Sahel region circa 5000 BC, when sorghum and African rice began to be cultivated. Around this time, and in the same region, the small guinea fowl became domesticated.

According to the Oxford Atlas of World History, in the year 4000 BC the climate of the Sahara started to become drier at an exceedingly fast pace.[17] This climate change caused lakes and rivers to shrink rather significantly and caused increasing desertification. This, in turn, decreased the amount of land conducive to settlements and helped to cause migrations of farming communities to the more tropical climate of West Africa.[17]

By 3000 BC agriculture arose independently in both the tropical portions of West Africa, where African yams and oil palms were domesticated, and in Ethiopia, where coffee and teff became domesticated. No animals were independently domesticated in these regions, although domestication did spread there from the Sahel and Nile regions.[18] Agricultural crops were also adopted from other regions around this time as pearl millet, cowpea, groundnut, cotton, watermelon and bottle gourds began to be grown agriculturally in both West Africa and the Sahel Region while finger millet, peas, lentil and flax took hold in Ethiopia.[19]

The international phenomenon known as the Beaker culture began to affect western North Africa. Named for the distinctively shaped ceramics found in graves, the Beaker culture is associated with the emergence of a warrior mentality. North African rock art of this period depicts animals but also places a new emphasis on the human figure, equipped with weapons and adornments. People from the Great Lakes Region of Africa settled along the eastern shore of the Mediterranean Sea to become the proto-Canaanites who dominated the lowlands between the Jordan River, the Mediterranean and the Sinai Desert.

By the 1st millennium BC ironworking had been introduced in Northern Africa and quickly began spreading across the Sahara into the northern parts of sub-Saharan Africa[20] and by 500 BC metalworking began to become commonplace in West Africa, possibly after being introduced by the Carthaginians. Ironworking was fully established by roughly 500 BC in areas of East and West Africa, though other regions didn't begin iron working until the early centuries AD. Some copper objects from Egypt, North Africa, Nubia and Ethiopia have been excavated in West Africa dating from around 500 BC, suggesting that trade networks had been established by this time .