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Unit 5: Human Population Dynamics // Glossary

carrying capacity
The number of individuals an environment can support without significant negative impacts to the given organism and its environment.
demographic convergence
When the gaps narrow between developed and developing countries for major indicators such as fertility rates and life expectancies.
demographic dividend
A rise in the rate of economic growth due to a rising share of working age people in a population.
demographic transition
The pattern of population growth exhibited by the now-developed countries during the 19th and early 20th centuries.
dependency ratio
The ratio of non-workers (children and retirees) to workers in a human population: the higher the ratio, the greater the dependency load.
fecundity
A measure of the capacity of an organism to produce offspring.
fertility
A measure of reproduction: the number of children born per couple, person, or population.
life expectancy
Term usually used at birth, indicating the average age that a newborn can be expected to attain.
migration
When living organisms move from one biome to another. It can also describe geographic population shifts within nations and across borders.
mortality
The loss of members of a population through death.
population momentum
The impetus for continued expansion of the number of people in a country when the age structure is characterized by a large number of children. Even if birth control efforts are effective in the adult community and the number of new births per person decreases, the number of people in the country expands as the large population of children reach reproductive age.
replacement level
The number of children per woman necessary to keep population levels constant when births and deaths are considered together over time; estimated to be an average of 2.1 children for every woman.

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