Population dynamics is the branch of life sciences that studies short-term and long-term changes in the size and age composition of populations, and the biological and environmental processes influencing those changes. Population dynamics deals with the way populations are affected by birth and death rates, and by immigration and emigration, and studies topics such as ageing populations or population decline.
Immigration is the movement of people into another country or region to which they are not native in order to settle there, especially as permanent residents or future citizens. Immigrants are motivated to leave their countries for a variety of reasons, including a desire for economic prosperity, political issues, family re-unification, escaping conflict or natural disaster, or simply the wish to change one's surroundings.
Traditional African patterns of settlement vary with differences in landscape and ecology, communications, and warfare. The most widespread pattern has been that of scattered villages and hamlets—the homesteads of joint and extended families—large enough for defense and domestic cooperation but rarely permanent because of the requirements of shifting cultivation and the use of short-lived building materials. Large mud-adobe villages are traditional in much of the western African savanna, but over most of Africa housing consists of mud and wattle with roofs of thatch or palm leaves.
Large towns were not widespread in the continent until the 20th century. Towns dating from precolonial times are found mainly along the Nile valley and the Mediterranean fringe of North Africa—where many date from Classical times (e.g., Alexandria, Egypt) and the late 18th century (e.g., Fès, Morocco)—and also in western Africa, in both forest and savanna zones, where they were the seats of governments of kingdoms. Timbuktu, Ife, Benin City, and Mombasa all date from the 12th century, while the city of Kano has prehistoric origins. Ibadan and Oyo became important cities only in the 19th century.
The more-traditional towns differ in form, function, and even population characteristics from the many towns and cities established under colonial rule as administrative, trading, or industrial centres and ports. These latter cities are found throughout Africa and include Johannesburg, Lusaka, Harare, Kinshasa, Lubumbashi, Nairobi, Dakar, Freetown, Abidjan, and many others; often, as in the case of Lagos or Accra, they are built onto traditional towns. Typically the focus of in-migration from an impoverished hinterland, they are ethnically heterogeneous. Many have grown to become the largest cities in their respective countries, dominating their national urban hierarchies in size as well as in function.
Mostly rural for centuries, Africa has rapidly become more urbanized. Although it is still the least urbanized of the continents, Africa has one of the fastest rates of urbanization. Thus, the total population living in towns—which was only about one-seventh in 1950—grew to about one-third by 1990 and about two-fifths in the year 2010. Generally, the level of urbanization is highest in the north and south, and it is higher in the west than in the east and nearer the coasts than in the interior.
The largest cities include Cairo, Alexandria, and Al-Jizah, Egypt; Kinshasa, Democratic Republic of the Congo; Lagos, Nigeria; Casablanca, Morocco; Johannesburg, South Africa; Addis Ababa, Ethiopia; and Algiers, Algeria. Many other large cities are seaports along the coasts or central marketing towns, linked by rail or river with a coast. Examples of seaports are Accra, Ghana; Lagos; and Cape Town, South Africa. Examples of large inland cities are Ibadan and Ogbomosho, Nigeria; Nairobi, Kenya; and Addis Ababa.
francis1897 answered the question on January 12, 2023 at 08:34