Section 1 – Studying Human Populations 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 Slow 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.

Cost of Growth Video Clip