1. Chapter 9
The Human Population

2. 9.1: Studying Human Populations
Describe how the size and growth rate of the human population has changed in the last 200 years
Define four properties that scientists use to predict population sizes
Make predictions about population trends based on age structure
Describe the four stages of the demographic transition
Explain why different countries may be at different stages of the demographic transition

3. 2 Categories for Countries:
Countries are often grouped by demographers into 2 general categories:
Developed countries—higher average incomes, slower population growth, and diverse industrial economies.
Developing countries—lower average incomes, simple and agriculture-based economies, and rapid population growth.

4. Human Population Growth
1800’s: exponential growth due to…
Increases in food production
Improvements in hygiene (eg. clean water and safe sewage disposal)
Industrial and scientific revolutions
Discovery of vaccines in the 20th century
Cannot continue…limited resources, competition, carrying capacity

5. Predicting Population Sizes (4)
Age structure
The distribution of ages in a specific population at a certain time.
Graphed in a population pyramid (lab!)
High growth rate more young than old
Slow or no growth  even distribution of ages
Survivorship
The percentage of members of a group that are likely to survive to any given age.
Survivorship curves: type I (most live to be very old), II (similar death rates at all ages), III (very poor, many children die)

7. Predicting Population Sizes (4)
Fertility rates: the number of babies born each year per 1,000 women in a population.
Also can calculate total fertility rate
Considers “replacement level”: the avg. number of children each parent must have in order to “replace” themselves.
Migration: mvmt. of individuals btwn. areas.
Immigration (in) vs. Emigration (out)

8. Reasons for Increases in Human Population Growth (or decline)…
Death rates decreased more rapidly than birth rates…causes???
Life expectancy (most affected by infant mortality); survivorship curve
1900 = age 40 w/ a high infant mortality rate
2000 = >age 67 (developed = 80+) w/ infant mortality at < 1/3 of the rate in 1900
Infant health is affected by…
-parents’ access to education, food, fuel, and clean water
Other threats?: density  increases in contagious diseases (e.g. AIDS, tuberculosis, Ebola)

9. HW!! Read through chapter 9  Pg. 239: The Demographic Transition
Take notes over the “stages of transition” and “women and fertility”
Checked in and discussed/questions tomorrow

10. 9.2 Changing Population Trends
Describe three problems caused by rapid human population growth
Compare population growth problems in more-developed countries and less developed countries
Analyze strategies countries may use to reduce their population growth
Describe worldwide population projections into the next century

11. 3 Problems…cause: rapid human population growth
Primary Problem: environmental; over consumption of resources; infrastructure.
1. vegetation…ex.: fuelwood
2. water…used for drinking, washing, & sewage disposal: waterborne diseases such as dysentery, typhoid, and cholera; ex. Lima, Peru.
3. land…shortage of arable (A.V.) land (land that is used to grow crops); urbanization (A.V.); “suburban sprawl”.

12. Managing Development and Growth
Strategies used include: family planning programs, economic incentives, legal punishments, public advertising, improvements in women’s status.
Result: worldwide fertility rates are dropping! Demographers predict that by 2050, most countries will have replacement level fertility rates  world population growth will _____(?)
World population = >7 billion and is still increasing.