The Human Population over Time

Forecasting Population Size: Age Structure & Survivorship

Forecasting Population Size: Fertility Rate and Migration

Life Expectancy

Demographic Transition

Ch. 9: The Human PopulationSection 1 Studying Human Populations

9.2

The Human Population over TimeAfter growing slowly for thousands of years, the human population begins to grow rapidly in the 1800’s. This growth is due to increases in food production and improvements in hygiene.

Forecasting Population SizeAge-Structure DiagramPopulation Pyramids compare the distribution of ages and sexes in a population.

Survivorship: the percentage of members of a group that are likely to survive to any given age.• Type I: most live to an

advanced age. Ex. Humans

• Type II: All ages have a similar death rate. Ex. Squirrels, birds

• Type III: Many offspring die Ex. Oysters, fish

Forecasting Population Size

Fertility Rates• Number of children a woman

gives birth to in her lifetime.• Replacement level fertility =

2.1

Key to decreasing fertility rates is educating women. Educated women find they do not need to have as many children and learn family planning techniques.

• Immigration- movement into an area

• Emmigration- movement out of an area.

• The US population has continued to grow because of births and immigration. The US has over 1 million immigrants a year.

Life Expectancy• The average number of years a population is likely to live

is life expectancy• Infant mortality- death rate of infants less than a year

old• Infant health is affected by: parents education, food, fuel and

clean water

Demographic Transition• Stage 1: Preindustrial

• Birth rate and death rate are both at high levels, population is stable.• Stage 2: Transitional

• Death rates decline as hygiene, nutrition and education improve, birth rates still high. Population grows very fast.

• Stage 3: Industrial• Birth rates decrease and population slows

• Stage 4: Postindustrial• Birth rates drop below replacement level, size of the population begins

to decrease

Problems of Rapid Growth

A Demographically Diverse World

Managing Development and Population Growth

Growth is Slowing

Fertility rates & Female Literacy in Africa

Ch. 9: The Human PopulationSection 2 Changing Population Trends

Problems of Rapid Growth1. Resource Depletion: • Vegetation, water and land are the

resources most critically affected by rapid population growth.

2. Shortage of Fuelwood: • In many poor countries, wood is the main

fuel source. • In many countries water must be sterilized

by boiling. Without fuelwood to do so, many people suffer from disease and malnutrition.

3. Unsafe Water: • in many places the local water is used for

drinking, washing and sewage disposal. As a result the water is infested with dysentery, cholera and typhoid.

• Many fast growing cities are unable to keep up with expanding their water systems.

4. Impacts on Land: • growing populations have a shortage of

arable land (land used to grow crops). • Urbanization (movement to cities) leads

to traffic jams, inadequate infrastructure, and reduction of land for farms and wildlife habitat.

A Demographically Diverse WorldLeast Developed Countries (LDC)• Three criteria as defined by the United Nations:

• Low income- less than $750 per year• Weak human assets- low nutrition, health, education and

adult literacy• Economic vulnerability- instability of agricultural

products and export of goods and services• These countries show few signs of development. Have

high birth rates and high death rates. Growth rates are much higher in less developed regions. Most of the worlds population is now in Asia

Managing Development and Population GrowthMillenium Development Goals (MDG)• Conference held in 1994 by the UN developed the MDG.• These goals aim at stabilizing population growth,

especially through improvements in women’s status.

• China found its growth overwhelming in the late1970’s and enacted the ‘One child Policy’. This policy was relaxed in 2014, allowing for couples to apply to have a second child.

Growth is SlowingCurrent world population is 7,293,600,000 • World population is still growing, but growth rates and

fertility rates have decreased (still high in LDC’s).• Demographers predict most countries will reach

replacement level fertility rates by 2050. if so, world population would eventually stop.

Fertility rates and Female Literacy in Africa

1. Which areas have the highest female literacy?

2. Lowest female literacy?

3. Highest fertility rates?

4. Lowest fertility rates?

Worldwide the average fertility rate is 2.8, and average female literacy is 74%. How does Africa compare?