Population Explosion

In sociology and biology a population is the collection of people or individuals of a particular species. A population shares a particular characteristic of interest most often that of living in a given geographic area. In taxonomy population is a low-level taxonomic rank.

Human populations can be defined by many characteristics such as mortality, migration, family (marriage and divorce), public health, work and the labor force, and family planning. Various aspects of human behavior in populations are also studied in sociology, economics, and geography.

Study of populations is almost always governed by the laws of probability, and the conclusions of the studies may thus not always be applicable to some individuals. This odd factor may be reduced by statistical means, but such a generalization may be too vague to imply anything. Demography is used extensively in marketing, which relates to economic units, such as retailers, to potential customers. For example, a coffee shop that wants to sell to a younger audience looks at the demographics of an area to be able to appeal to this younger audience.

According to papers published by the United States Census Bureau, the world population hit 6.5 billion (6,500,000,000) on January 25, 2006. The United Nations Population Fund designated October 12, 1999 as the approximate day on which world population reached 6 billion. This was about 12 years after world population reached 5 billion, in 1987. However, the population of some countries, such as Nigeria, is not even known to the nearest million,[citation needed] so there is a considerable margin of error in such estimates.