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Delve into the study of human populations in developed and developing countries, understanding demographic shifts over time, age structures, survivorship, fertility rates, migration patterns, declining death rates, life expectancy, and the demographic transition. Explore how women's roles and societal changes influence population growth with an emphasis on cost and benefits.
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The Human Population Section 1 – Studying Human Populations
Studying Human Populations • Demography - study of the characteristics of human populations
Developed and Developing Countries • Developed - higher average incomes • slower population growth • diverse industrial economies • stronger social support systems.
Developed and Developing Countries • Developing - lower average incomes • simple and agriculture-based economics • rapid population growth.
The Human Population Over Time • Exponential growth in the 1800s • population growth rates increased during each decade • Increases in food production • Improvements in hygiene • industrial and scientific revolution.
The Human Population Over Time • Unlikely Earth can sustain this growth for much longer
Age Structure • Age structure - classification of members of a population • Grouped by age or distribution of members of a population in terms of age groups • helps demographers make predictions
Age Structure • High rates of growth • more young people than older people. • Slow rates of growth • even distribution of ages in the population.
Survivorship • Survivorship - percentage of newborns that can be expected to survive to a given age • predict population trends
Survivorship • Wealthy countries • Type I survivorship curve • most people live to be very old. • Type II populations - similar death rate at all ages. • Type III survivorship • very poor human populations in which many children die. • Both Type I and Type III may result in populations that remain the same size or grow slowly.
Fertility Rates • Fertility rate - number of births per 1,000 women of childbearing age (usually 15 to 44). • Replacement level - average number of children each parent must have in order to “replace” themselves.
Migration • Migration- any movement of individuals or populations from one location to another. • Movement into an area is immigration and movement out of an area is emigration.
Declining Death Rates • Increase in Earth’s population in last 200 years • death rates have declined more rapidly than birth rates. • Vaccines • Clean water • Food
Life expectancy • Life expectancy -average length of time that an individual is expected to live. • Affected by infant mortality, the death rate of infants less than a year old.
Demographic Transition • Demographic transition - general pattern of demographic change from high birth and death rates to low birth and death rates • observed in the history of more-developed countries.
Transition Stages • 1st stage – preindustrial stage • 2nd stage – population explosion • 3rd stage – population slows • Birth rate decreases • 4th stage - birth rate drops below replacement level
Women and Fertility • Lower death rate of the second stage is usually the result of increased levels of education. • Women are able to contribute to their family’s increasing prosperity while spending less energy bearing and caring for children.
