Population © Robert J. Atkins, Ph.D. What are six basic demographic (population) terms? Demography The study of human population Fertility Amount of childbearing in a population Several measurements of this Demographic terms (cont.) Crude birth rate Live births per 1,000 people each year High income nations e.g. U.S. = lower than average crude birth rate The lower the average income, the higher the population increase Demographic terms (Cont.) Fecundity rate Maximum possible childbearing Sex Ratio Males for every 100 females Zero Population growth (ZPG) Two people produce two people Maintains population at a steady state Do you remember? What are the six basic demographic terms? What do they measure? What is the world population? Currently 7 Billion Most of human history the population of the entire earth was 500 Million (1/2 billion) Something to think about: Why do developing nations contribute so much more to the world population? Why do people have so many children? Through Birth most of human history: control was not reliable Children were needed for the farm High death rates = many children did not reach adulthood What is the Malthusian theory? Food increasing arithmetically Pop. Increasing geometrically Result : People reproducing beyond what the planet can support Out-stripping resources Poisoning the planet What is the Malthusian theory? Population increases geometrically Food increases arithmetically Population could increase beyond what the planet could support Population Food What is the Demographic Transition Theory? Population patterns reflect a society’s level of technological development From preindustrial (high births & deaths) = slow population growth To postindustrial (low births & deaths) = slow or stable population growth Between these two, high birth rate & low death rate = rapidly expanding population Do you remember? What is the current world population? Why did people have so many children? What is the Malthusian theory? What is the Demographic Transition theory?