the variety of species in nature and the genetic diversity within each species
the number of people who can be supported at a sustainable level in an area with given resources and technology
lack of proper nutrition, caused by not having enough to eat
he prevention of disease and promotion of good hygiene by maintaining clean conditions and safe drinking water
the study of human populations, including how they change due to births, deaths, aging, and migration
a scientist who studies the characteristics of human populations, such as size and growth rate
graph that shows the ages and sexes in a population, with the youngest ages displayed at the bottom and the oldest at the top. The shape of a population pyramid reflects how a country's population is growing.
an age group on a population pyramid
the number of old and young dependents who do not work compared with the working-age population. The higher the ratio, the more young and old people the workers have to support.
the total fertility rate needed for a population to replace itself. This number varies by country, but it is about 2.1 in most developed countries.
total fertility rate (TFR)
the average number of children a woman in a given population will have in her lifetime. This number is different in different countries.