Population

© Robert J. Atkins, Ph.D.1

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What are six basic demographic (population) terms?Demography

The study of human populationFertility

Amount of childbearing in a population

Several measurements of this

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Demographic terms (cont.)

Crude birth rateLive births per 1,000 people each

yearHigh income nations e.g. U.S. =

lower than average crude birth rateThe lower the average income, the

higher the population increase

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Demographic terms (Cont.)

Fecundity rateMaximum possible childbearing

Sex RatioMales for every 100 females

Zero Population growth (ZPG)Two people produce two peopleMaintains population at a steady state

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Do you remember?

What are the six basic demographic terms?

What do they measure?

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What is the world population?

Currently7 Billion

Most of human history the population of the entire earth was 500 Million (1/2 billion)

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Why do developing nations contribute so much more to the world population?

Something to think about:

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Why do people have so many children?

Through most of human history:Birth control was not reliableChildren were needed for the farmHigh death rates = many children did

not reach adulthood9

What is the Malthusian theory?

Food increasing arithmeticallyPop. Increasing geometricallyResult : People reproducing beyond

what the planet can supportOut-stripping resourcesPoisoning the planet

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What is the Malthusian theory?

PopulationFood

Population increases geometrically

Food increases arithmetically

Population could increase beyond what the planet could support

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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

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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?

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