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Human Populations. Melody Bender . F actors that affect Human Populations: . Historical Population Sizes Population Distribution Fertility Rates Growth Rates Doubling Times Demographic Transition. http://www.youtube.com/watch?v=sc4HxPxNrZ0. Historical Population Sizes.
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Human Populations Melody Bender
Factors that affect Human Populations: • Historical Population Sizes • Population Distribution • Fertility Rates • Growth Rates • Doubling Times • Demographic Transition • http://www.youtube.com/watch?v=sc4HxPxNrZ0
Historical Population Sizes • The rapid growth in population is due mainly to the decrease in death rates. • Several Factors that Reduce Death Rates: • Increased food and efficient distribution (better nutrition) • Medical and Public Health Technology Improvements • Improvements in sanitation and personal hygiene • Safer Water Supplies • 3 Historical Surges in Population • The use of tools and fire • The agricultural Revolution • The Industrial and Medical Revolution • Population Change= (crude birth rate + immigration) – (crude death rate + emigration) • The Actual Growth Rate= (birth rate – death rate)/10 • The current growth rate is approximately 1.3%
Distribution: • Places with the most growth: Africa, Asia, and Latin America. (Less developed countries) • Places with slow growth: Europe and North America • Places with negative growth: Russia, Germany, Italy, and Japan
Fertility Rates: • Replacement Level Fertility(RLF)- the level of fertility at which a couple has only enough children to replace themselves, or 2 children per couple. • It takes a RLF of 2.1 to replace each generation. • RLF rates are lower in moderately developed countries, and higher in less developed countries due to high infant mortality rates. • Total Fertility Rate(TFR)- the average number of children that each woman will have during her lifetime. • Highest to Lowest Fertility Rates: Niger(7.46), India(2.73), Mexico(2.42), Israel(2.41), USA(2.09), China(1.73), European Union(1.47), Japan(1.4), Russia(1.28), Hong Kong(.95) geography.about.com/od/populationgeography/a/fertilityrate.htm
Declines in Fertility Rates are caused by: • Higher cost of living • Decrease in demand for children to work on farms • Contraception/Abortion • Increase in educated females and females in the workforce • Desire to increase standard of living • Postponing marriage due to careers
La LaLa RANDOM! Rule of 70 Strategies to sustain population size: To find the doubling time of a quantity growing at a given rate, divide the percentage number into 70 to obtain the approximate number of years required to double. Ex.: 70/ 2%= 35 years Provide economic incentives to have fewer children Empower and educate women Education-> Higher incomes-> less children Higher education leads to having children later in life
Demographic Transition: • The name given to the process that has occurred during the past century. Has four stages. • Stage 1: Pre-Industrial • Living conditions severe, medical care is non-existent, and food supply is limited, etc • Stage 2: Transitional • Stage after the start of industrialization. • Stage 3: Industrial • Urbanization decreases the economic incentives for large families, cost of living increases, increase in opportunities for women, etc. • Stage 4: Post-Industrial • birth rates=mortality rates, zero population growth is achieved, standard of living is high, etc. http://geography.about.com/od/culturalgeography/a/demotransition.htm
Age Structure Diagrams: • Determined by birth rate, generation time, death rate, and sex ratios. It is a good indicator of future trends in population growth.
Which step of Demographic Transition is prior to the Industrial Revolution? • The First Step • The Second Step • The Third Step • The Fourth Step • The Fifth Step
Where are Replacement Fertility Rates the lowest? • Developed Countries • Less Developed Countries
When was the last historical surge in population? • After the use of tools and fire • After The Agricultural Revolution • After the Medical/Industrial Revolution
Which of the following countries is having negative growth? • The United States • Australia • Germany • Brazil