The Human Population

Studying Human Population

Chapter Nine

Section One

Demography – study of populations

• Developed countries– Higher average income

– Slower pop. growth

– Diverse industrial economy

– Strong social support systems: health care, family support, food services

• Developing countries– Lower average income

– Simple and agricultural based economies

– Rapid population growth

Exponential population growth

Age structure diagrams

• Distribution of ages in a specific population at a certain time

• Can be graphed as a population pyramid – a double sided bar graph

Population Pyramids

Survivorship Curves

• Survivorship – percentage of members of a group that are likely to survive to any given age

• Type I – wealthy developed countries, most people live to old age

• Type II – similar death rate at all ages

• Type III – many children die

Fertility Rates and Migration

• Fertility rate - # of babies born each year per 1000 women

• Migration – movement of individuals between areas

• Immigration – movement in (keeping population of developed nations from decreasing)

• Emigration - movement out

Fertility rates in the U. S.

Declining Death Rates

• Death rates declined more than birth rates because of clean water, adequate food, safe sewage disposal, vaccines

• Life expectancy – average number of years a person is expected to live– Most affected by infant mortality, the death rate

of infants less than 1 year old