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1. THE HUMAN POPULATION
Ch. 9, Section 1: Studying the Human Population
Standards: SEV5a, b

2. WHAT IS DEMOGRAPHY?
 Demography- study of
populations, especially
human populations.
 Includes study of:
 Historical size of
population
 Make up of population
 Economics
 Social structure
 Demographers use this
info. to make
comparisons &
predictions about
populations.

3. WHAT 2 CATEGORIES DO DEMOGRAPHERS
GROUP COUNTRIES INTO?
1. Developed Countries
 Have higher avg. incomes
 Slower pop. growth
 Diverse industrial
economies
 Ex: US, western Europe

4. WHAT 2 CATEGORIES DO DEMOGRAPHERS
GROUP COUNTRIES INTO?
2. Developing Countries
 Lower avg. incomes
 Simple, agricultural
based economies
 Rapid population growth
 Ex: India, China,
countries in Africa

5. HOW HAS THE HUMAN POPULATION CHANGED
OVER TIME?
 Population grew slowly
for 1000’s of years
 In 1800’s (Modern Age)
population grew
exponentially
 Due to increase in food
supply & better hygiene
thanks to industrial &
scientific revolutions
 Human population
continues to grow
exponentially… will it
ever reach its carrying
capacity?

6. HOW CAN A POPULATION BE PREDICTED?
 Demographers look at
many properties of
populations to predict:
 Will community need
more schools?
 Will community need
more retirement homes
 Will population increase
to point where we need
more roads & utilities?

7. HOW CAN A POPULATION BE PREDICTED?
 Demographers use
numerous tools and
graphs to predict
populations:
 Age structure graphs
 Survivorship curves
 Fertility rates
 Migration patterns

8. AGE STRUCTURE GRAPHS
 Graph that shows the
distribution of ages in a
specific population at a
certain time.
 A.K.A. population pyramids
 Parts of an age structure
graph:
 Bars = ages
 Colors = gender
 Numbers on bottom=
percentage of the population
 3 Categories of Age Structure
Graphs
 Rapid growth
 Slow growth
 Declining/zero growth

9. AGE STRUCTURE GRAPHS
 Rapid growth
 Young people
dominate population
 Has population
momentum- more
children will move up
to become
reproductive
 Rapid increase in birth
rates once the
youngsters reach
reproductive age.
 EX: Developing
countries- many
countries in Africa,
Mexico, S. America

10. AGE STRUCTURE GRAPHS
 Slow Growth
 Birth rates = death
rates
 All age groups are
about equal
 EX: Most Western
European countries,
U.S.

11. AGE STRUCTURE GRAPHS
 Declining Growth
(Zero growth)
 Birth rates are lower
than death rates
 Many more older
people who are not
reproducing
 Fewer younger people
 Population will become
much smaller when
they die.
 Ex: Germany, Russia

12. SURVIVORSHIP CURVES
 Percentage of members of a
group that are likely to
survive to any given age.
 Follows a group of
organisms from the time they
were born to the time they
die to see trends.
 3 Types of Survivorship
curves:
 Type I
 Type II
 Type III

13. SURVIVORSHIP CURVES
 Type I
 Lots of offspring survive and live
to old age.
 Ex: Developed countries- US,
Japan
 Ex: Zebras, Bears, etc.
 Type II
 Populations have a similar death
rate at all ages
 Ex: birds
 Type III
 Lots of offspring die young & very
few survive to old age.
 Ex: Developing countries- Africa,
Asia
 Ex: insects, clams

14. FERTILITY RATES
 Fertility rate- number of babies
born each year per 1,000
women in a population.
 Total fertility rate- avg.
number of children a woman
gives birth to in her lifetime.
 Replacement level fertility-
avg number of children each
parent must have in order to
“replace” themselves in the
population.
 RLF = approximately 2 children
 Compare Zambia to Europe
using the chart to the right.
 What conclusions can you draw
based on this data?
Highest
(Zambia)
Lowest
(W.
Europe)
Lowest
(E.
Europe)
Total
Fertility
Rate
6.7 1.3 1.4
GNP/capita/
year
$225 $19,000 $3108
Life
expectancy
47.6 yrs 77.6 yrs 68.9 yrs
Birth Rate
per 1000
47.6 9.7 9.9
Death Rate
per 1000
17.6 10.0 13.0
Infant
Mortality
Rate per
1000
120 7 22
Annual
Growth
Rate
2.9% 0.1% -0.4%

15. FERTILITY RATES
 Keeping total fertility rate
below replacement level
fertility will help populations
decline.
 This graph shows US
population change since 1920.
 Who are the baby boomers?
Lots of babies were born post
WWII…when soldiers returned
home from war ;)
 Why did population start rising
in the 1990’s? Children of baby
boomers were growing up &
having kids

16. MIGRATION PATTERNS
 Immigration-
movement into an area
 Emigration-
movement out of an
area
 US experiences lots of
immigration… would
our population decline
if we didn’t have
immigration?

17. WHAT FACTORS AFFECT A COUNTRY’S DEATH
RATE?
 Life expectancy- avg. number
of years members of a
population are likely to live.
 Most affected by infant
mortality- death rate of infants
less than a year old.
 Infant mortality (death rates)
have decreased and life
expectancy has increased due
to access to
 adequate food
 clean water
 safe sewage disposal
 vaccines (around beginning of
20th century)
 access to education
Worldwide Infant mortality rates

18. WHAT FACTORS AFFECT A COUNTRY’S DEATH
RATE?
 Threats to life
expectancy :
 As populations
increase, population
becomes denser
 Disease can spread
quickly thru dense
populations.
 Ex: AIDS, tuberculosis
 This will increase death
rate and decrease life
expectancy.
Sign located in South African
village.

19. WHAT FACTORS AFFECT A COUNTRY’S BIRTH
RATE?
 Birth rates typically are
lower in areas where:
 Women are educated
 Academically
 Family planning techniques
 Women are economically
independent
 Have jobs
 So less time for raising many
children.
 Pensions are available for
elderly
 no need for kids to help take
care of elderly

20. WHAT FACTORS AFFECT A COUNTRY’S BIRTH
RATE?
 Large families are
common when children
are needed to work
and take care of older
family members
 As countries
modernize, there is
less need for lots of
kids.
 This can decrease birth
rates.

21. WHAT FACTORS AFFECT A COUNTRY’S BIRTH
RATE?
 Factors that can increase
a population’s birth rate:
 Lack of birth control due
to availability or religion
 Need to have children b/c
have poor health care
and children can die
easily
 Women are uneducated,
repressed, with no rights
to make decisions about
their own bodies.

22. WHAT IS THE DEMOGRAPHIC TRANSITION?
 Pattern of falling death
rates & birth rates due to
improved living
conditions.
 All countries should
experience this trend in
population change.

23. WHAT ARE THE STAGES OF DEMOGRAPHIC
TRANSITION?
 Preindustrial societies-
 Higher birth rates- due to
need for kids to help on
farm; have lots of kids
because many will die
from disease/malnutrition.
 Higher death rates- due
to food shortages,
malnutrition, lack of
sanitation & medicine,
accidents, other hazards
 Population is low
because of high death &
birth rates.

24. WHAT ARE THE STAGES OF DEMOGRAPHIC
TRANSITION?
 Industrialization-
 Decreasing death rates-
due to improved health
care and sanitation.
 Continuing high birth
rates- people still having
lots of kids because
healthcare is not
widespread and may be
ignorant about birth
control
 People have better jobs,
more income, more
people surviving due to
rise in standard of living.
 Population grows
exponentially.

25. WHAT ARE THE STAGES OF DEMOGRAPHIC
TRANSITION?
 Mature Industrial
 Death rates continue
declining
 Birth rates begin
declining
 Women realize they
don’t need as many kids
 Women realize how
expensive kids are
 Women may have jobs
so less time for kids

26. WHAT ARE THE STAGES OF DEMOGRAPHIC
TRANSITION?
 Postindustrial
societies-
eventually BR & DR
level out &
population is at
equilibrium. W.
Europe saw this in
19th & 20th century