Human Populations Flashcards
What is the biggest factor in declining birth rates? Why?
- Increasing education & economic independence is the largest factor in a decline in birth rates
- Educated women find that they do not need to bear as many children to ensure that some will survive. They may also learn family planning techniques.
Why are there lower birth rates in both developed & developing countries?
- Women are able to contribute to their family’s increasing prosperity while spending less energy bearing & caring for children.
As countries modernize, parents are more likely to work away from home. If parents must pay for child care, children may become a financial burden rather than an asset.
Population Change Equation
(Births + Immigration) - (Death + Emigration)
Child mortality
number of deaths of children under age 5 per 1,000 live births
Infant mortality
number of deaths of children under 1 year of age per 1,000 live births
Life expectancy
average number of years that an infant born in a particular year in a particular country can be expected to live, given the current average life span & death rate in that country
What factors are associated with infant mortality rates?
Factors associated with infant mortality rates include:
Whether mothers have access to good healthcare & nutrition, education (including family planning resources, knowledge of contraception, how to take care of children, etc.), access to clean water and fuel
What is the average replacement level worldwide? What does it mean if the fertility rate is at replacement levels? How does the replacement level of developing countries differ, and why?
- If fertility rate is at replacement levels, a population is considered relatively stable.
- Total fertility rate required to offset the average number of deaths in a population in order to maintain the current population size.
- Replacement level: average number of children each parent must have in order to “replace” themselves. This number is slightly more than 2 (2.1 to be exact) because not all children born will survive & reproduce.
- Replacement level fertility tends to be higher in developing countries because mortality among young people tends to be higher.
Total fertility rate (TFR) is affected by:
Age at which females have their first child, Educational opportunities for females, Access to family planning, & Government acts & policies
Total fertility rate (TFR)
Estimate of average number of children that each woman in a population will bear throughout her childbearing years
How do the age structures of rapidly growing populations generally look?
A rapidly growing population will, as a rule, have a higher proportion of younger people compared to stable or declining populations.
What happens when the resource base of a population is stable? What happens when the resource base of a population is disturbed?
- When the resources needed by a population for growth are abundant, population growth usually accelerates.
- When the resource base of a population shrinks, the increased potential for unequal distributions of resources will ultimately result in: increased mortality (death),
decreased fecundity (ability to produce offspring),
or both, resulting in population growth declining to, or below, carrying capacity.
How does the age of marriage affect population growth?
If the age of marriage is late, population growth is slowed. If the age of marriage is earlier, population growth is sped up.
What affects whether a human population is growing or declining?
Birth rates/ infant mortality rates
overall death rates / access to family planning / access to good nutrition / access to education / postponement of marriage
Factors limiting global human population include:
- Earth’s carrying capacity &
- Basic factors that limit human population growth as set forth by Malthusian theory.
What is the Malthusian theory? Has it been proven true or false? Why?
Hypothesis: world population grew exponentially (1, 2, 4, 8, 32, 64…) but agricultural production grew arithmetically (1, 2, 3, 4, 5, 6, 7…) making it inevitable that Earth, at some time, would not be able to produce enough food for all its inhabitants.
- The theory was proven false because research variables were included (such as wars & famines) but he could not conceive important emerging variables in future decades (such as birth control techniques & technical advances applied to agriculture & food production).
What is the Rule of 70? What unit is used for the growth rate of a population?
Dividing the number 70 by the % population growth rate approximates population’s doubling time.
70/r = Population doubling time
(r = growth rate of a population in % NOT decimal)
What are symptoms of overwhelming populations in a country?
- suburban sprawl
- polluted rivers
- barren land
- inadequate housing
- overcrowded schools.
What conflicts over land availability arise when populations grow rapidly? How does population growth affect the availability of arable land?
- Growing populations may have a shortage of arable land.
- Growing populations also make trade-offs between competing uses for land such as agriculture, housing, or natural habitats
What is arable land?
Arable land - farmland that can be used to grow crops.
Food security
condition in which people have access to sufficient, safe, & nutritious food that meets their dietary needs for an active & healthy life
What causes starvation on a global scale?
Starvation on a global scale - result of unequal distribution of food rather than absolute scarcity of food
- Political and economical factors also play a role
How does net migration rate affect the global population?
- Net migration rate - difference between immigration & emigration in a given year per 1,000 people in a country.
- Regardless of birth & death rates, a country may experience population growth, stability, or decline as a result of net migration.
How has population growth on Earth changed dramatically over the last two centuries?
- Dramatic increase in Earth’s human population in last 200 years occurred because death rates have declined more rapidly than birth rates.
- Exponential growth due to increases in food production & improvements in hygiene during industrial & scientific revolution.
- Declining death rates are due to access to adequate food, clean water & safe sewage disposal along with medicines & vaccines - for individuals with access