T/F: the human population has grown faster in the 20th century than it ever has before
The rapid growth in what has caused environmental problems all around the world?
study of populations, but most often refers to the study of human populations
what do demographers study?
historical size and makeup of the populations of countries in order to make comparisons and predictions; they also study properties that affect population growth such as economics and social structure.
2 general categories of countries in terms of demography
developed countries and developing countries
higher than average incomes, slower population growth, diverse industrial economies
lower average incomes, simple and agriculture based economies and rapid population growth
Occurred in the 1800’s, meaning population growth rates increased during each decade
what caused the expenential growth of the 1800’s?
increases in food production, improvements in hygeine that came with the industrial and scientific revolutions
Is it likely that the earth can continue to sustain exponential growth in the future?
what are the 4 properties that scientists use to predict population sizes?
age structure survivorship fertility rates migration
a type of double sided bar graph that shows typical age structures for countries that have different rates of growth
Countries that have high rates of growth usually have what?
more young people than old people
Countries that have slow growth or no growth usually have what?
an uneven distribution of ages
percentage of members of a group that are likely to survive to any given age
how is survivorship studied?
studies a group of people born at the same age and notes when each person dies
survivorship type I
most people live to be very old
survivorship type II
people have a similar death rate at all ages
survivorship type III
usually very poor human populations in which many children die
number of babies born each year per 1000 women in a population
total fertility rate
average number of children a woman gives birth to in her lifetime
when did the total fertility rate drop below the replacement level in the US?
1972, the first time in US history; the rate remained below replacement level for most of the 1990’s
the average number of children each parent must have in order to replace themselves in the population
Why did the population of the US continue to grow from 1970 to 2000?
baby boomers had kids and immigration
Why has human population increased dramatically in the past 200 years?
death rates have declined more rapidly than birth rates (less people are dying that being born)