APES Chapters 8 & 9


Terms in this set (...)

What percent of growth is in DEVELOPING countries?
Replacement-level Fertility
# Of children a couple must bear to replace themselves.
Three major factors influencing population increase:
1) Humans developed the ability to expand into diverse habitats and different climate zones.
2)The emergence if early and modern agriculture allowed more people to be fed per unit of land.
3)Developed sanitation systems, antibiotics, and vaccines to help control infectious diseases.
What is the population growth rate like today?
The rate of population growth has slowed but is still growing rapidly.
Optimum sustainable population
Allow most people to live in reasonable comfort and freedom without impairing the ability of the planet to sustain future generations.
Calculation of Population change
Population change=(Births + Immigration)-(Deaths + Emigration)
Three factors affecting human population:
1)Births (fertility)
2) Deaths(mortality)
Birth rate, Crude birth rate
# of live births per 1,000 people in a population in a given year.`
Death rate, Crude death rate
# of deaths per 1,000 people in a population in a given year.
What country had the largest birth and death rates?
What countries has the largest number of people in them?
China and India
# of children born to a woman during her lifetime.
Why is the replacement-level fertility slightly higher than two?
Because some children die before reaching their reproductive years.
Does reaching replacement-level fertility bring an immediate halt in population growth?
No, because there are still more future parents alive than the numbers of elders alive. Future parents would have to have an average of 2.1 children and their children have 2.1 children, and then the worlds population would still continue to grow for 50 years or more. (In order to level the population out)
Total fertility rate
The average # of children a woman typically has during her reproductive years.
Baby boom
Period of high birth rates between 1946-1964, adding 79 million people to the US and increasing the TFR to 3.7 children per woman.
Baby bust
Period after the baby boom where not as many babies were born. Due to delayed marriage, widespread contraceptive use, and abortion.
Lifestyle changes within the last century within the US:
1) In 1905, the leading cause of death in the US was pneumomonia, tuberculosis, and diarrhea
2)90% of US doctors had no college education
3) 1 out of 5 adults could not read or write
4) The average US worker earned $200-400 per year and the average daily wage was 22 cents per hour.
5)only 9,000 cars in the US
6)most women washed their hair only once a month
7)a 3 minute phone call from Denver, Colorado, to New York City was $11
8)Only 30 people lived in Las Vegas, Nevada
9) only 232 kilometers (144 miles) of paved roads
Factors affecting birth rates and fertility rates:
1)Importance of children in the labor union
2)Cost of raising and educating children-in developed countries, children are much more costly because they do not enter the work force till their late teens and/or twenties.
3)Availability of public and private pension systems-can affect the amount of children a couple has, based on whether it reduces the need to have many children to help support them In old age.
4)Urbanization-People living in urban areas usually have better access to family planning services and have less children, whereas those in rural areas need them to perform essential tasks.
5)Educational and employment opportunities available for women-Women who have access to an education ad paying employment outside tend to have less children than those in developing countries with no education or job.
6)Infant morality rate- In areas where the infant morality rate is low, people tend to have less children because not as many will die at a young age.
7)Average age of marriage(or birth of first child)-Women tend to have less children when their wedding age is 25 or older.
8)Availability of legal abortions.
9)Availability of reliable birth control methods-Allows women to control the number and spacing of the children they have.
10)Religious beliefs, traditions, and cultural norms-Some countries these factors favor large families and strongly oppose abortion and some forms of birth control.
Life expectancy
The average number ofyears a newborn infant can be expected to live.
Infant morality rate
# of babies out of every 1,000 who die before their first birthday.
What three factors keeps infant morality higher than it should be?
1)Drug addictions among pregnant women
2)High teenage birth rate
3)Inadequate pre and post natal care for poor people
Death from AIDS
(Africa) They don't actually die from AIDS, but from dehydration, which leads to diarrhea. It mostly kills young adults because the old adults are already dead, and also because the young people have sex and sleep around more often, leading them to get exually transmitted diseases easier(such as AIDS). Developing countries do not have the ame technology access that developed countries have to help cure these diseases.
The movement of people into(immigration) and out of(emigration) out of a specific geographic area.
Reasons for Migration:
1)Seeking jobs and economic improvement
2)Religious persecution, ethnic conflict
3)Political oppression
5)Environmental degradations (Water shortages, soil erosion, deforestation, desertification, population pressures, and severe poverty).
Why do we need immigrants?
They pay taxes and take many menial and low-paying jobs that most other americans shun, open businesses and create jobs.
Age structure
The distribution of males and females in each age group in the worlds population.
What are some perks to being apart of the baby bust generation?
1)Fewer people will be competing for educational opportunities, jobs and services.
2)Labor shortages may drive up their wages, at least for jobs that require education or technical training beyond high school.
What are some cons to being apart of the baby bust period?
1)May find it hard to get promotions as they reach middle age because members of the baby boom will still be holding their high positions. Also the baby boomers may delay retirement because of improved health, the need to make save enough money for retirement funds, or the extension of retirement age which they can collect social security.
Why is decreasing population growth bad>?
It leads to economic and social problems, such as during a baby bust the amount of elderly people exceeds the young people and it puts strains on the governments budgets because older people require a large share of medical care, social security funds, and other costly public services funded by a decreasing number of working tax payers.
Why would global aging make military actions increasingly difficult for many nations?
1)There will be fewer young people available for military service.
2)Parents with only one or two children will be increasingly reluctant to support military ventures that could wipe out their offspring.
3)As the costs of health care and pensions rise and as the labpr force stops growing, there will be intense competition between general populace and the military for limited and perhaps decreasing governmental funds.
Two ways to decrease the spread of AIDS:
1) improved education and health care.
2) Provide financial assistance for education and health care as well as volunteer teachers and health care and social workers to help compensate for the missing young-adult generation.
Demographic Transition
A hypothesis of population change among the western European countries that became industrialized.
*As countries become economically developed, their birth and death rates tend to decline.
Preindustrial Stage
Little population growth because of harsh living conditions (high birth rate and high death rate).
Transitional Stage
Industrialization begins (food production rises and health care improves). Death rates drop and birth rates remain high (population growth).
Industrial Stage
Birth rate drops and eventually approaches death rate.
Postindustrial Stage
Birth rates continues to decline and equals the death rate, reaching a zero population growth.
What stage is most developing countries in today?
Transitional stage
Family planning
Provides educational and clinical services that help couples choose how many children to have and when to have them.
What are the three factors leading women to have fewer and healthier children?
2)Holding a paying job outside the household
3)Do not have their human rights supressed
What is the best way to slow population growth?
1)Investing in family planning
2)Reducing poverty
3)Elevating the status of women
Has a serious problem of poverty, malnutrition, and environmental problems.
*1 of every 4 people is poor.
*Half of the country's labor force is unemployed or can find only occasional work.
*40% of its people suffer from malnutrition because of poverty.
*17% of the worlds people and only 2.3% of the worlds land resources and 2% of the worlds forests.
*Half of the country's cropland is degraded in result to soil erosion, waterlogging, salinization, overgrazing, and deforestation.
*More then 2/3 of the water is polluted
*Air pollution in many of its major cities
*Undergoing rapid economic growth
*No family planning, therefore increased population growth (low status of women there)
*Believe they need to have many children to take care of them when older, and a strong cultural preference for males results in continuous pregnancies to produce more males. (Cultural preference to avoid birth control).
*One state influences women to be sterilized after one or two children and receives a small cash payment after doing so.
Has used a government enforced program to cut its birth rate in half and sharply reduce its fertility rate.
*Has moved 300 million people out of poverty and quadrupled the average persons income and has boosted life expectancy to 72.
*The only other way to control population is mass starvation so other than that they implemented the most strict family planning and population control program.
*Discourages premarital sex, urges people to dealy marriages and limit families to no more than one child per family. Married families who pledge to have only one child gets benefits such as more food, larger pensions, better housing, free health care, salary bonuses, free school tuition for their child and preferential employment opportunities when their child enters the job market. Couples who break their pledge lose such benefits.
*Government provides married couples with free sterilization, contraceptives, and abortion.
*Strong preference for males, resulting in abortions of female fetuses and a significantly higher amount of males in china than females. Also females more likely to marry and runoff from family and not take care of their parents when older. Now, with the girls that are left, teenage girls are kidnapped and sold as brides to single men throughout the country.
*Chinas economy is growing at one of the worlds highest rates as the country undergoes rapid industrialization
*Problem with environmental degradation- supplies of some renewable resources are exceeding the rising demand and increased resource use is polluting the air and water.
*With fewer children, the average age of Chinas population is increasing rapidly, which could result in a declining work force, lack of funds for supporting continuing economic development, and fewer children and grandchildren to care for the growing number of elders.
Altering nature to meet our needs:
1) Relying mostly on polluting fossil fuels.
2) Reduction of biodiversity
3)Elimination of many natural predators
4)Using some renewable resources faster than they can be replenished.
Two major things we need to do to maintain earth:
1)Need to maintain a balance between simplified, human-altered communities and the more complex natural communities on which we and other species depend on.
2)We need to slow down the rates at which we are simplifying and degrading nature for our purposes.
People who oppose population regulation are least likely to say that...
increasing human population threatens the earths life-supporting systems.
The change that takes place in a demographic transition occurs when
the economic development of a country changes the population growth pattern.
The success of a family planning program is enhanced when
Contraceptives are widely used.
Economic rewards and penalties in population control strategies work best if they
reinforce existing customs and trends.
Death rates have declined because....
1)Increased food supply
2)Advances in medicine
3)Improved Sanitation and personal hygiene
4)Safer water supplies
Why are there more women than men in older ages?
Women live longer because of mens more dangerous professions and hobbies
*Military, construction workers, law enforcement...Those are all dangerous jobs and have a high death rate whereas most women do not work in highly dangerous professions.
Should age structure diagrams help you figure out what it is you want to study in college?
Shows the fields that are necessary to do that stuff.
Population Dynamics
Study of how and why populations change in their distribution, numbers, age structure and density in response to changes in environmental conditions.
Three types of population distribution:
2)Uniform dispersion (Creosote)
3)Random Dispersion
Clumping (why.. 4 reasons)
Most species live here.
1)The resources necessary for a species vary greatly in availability from place to place.
2)Living in herds, flocks, etc. provide protection.
3)Gives predator species a better chance of getting a meal.
4)Form mating groups within the "clump"
Bushes in a desert have better access to scarce water resources.
Random dispersion
Very rare to have organisms here.
The three stages of Age Structure
1)Preproductive-not mature enough to reproduce
2)Reproductive-those capable of reproduction
3)Postreproductive-Too old to reproduce.
Fun fact
Population wants an even amount of each group to remain stable. Reproduction by younger people balances by the deaths of older individuals.
Intrinsic rate
Rate at which a population would grow if it had unlimited resources.
Individuals in populations with a high intrinsic rate of growth typically...
1)Reproduce early in life
2)Have short generation times
3)Can reproduce many times
4)Have many offspring each time they reproduce
Carrying capacity
The maximum population of a given species that a particular habitat can sustain indefinitely without degrading the habitat.
Environmental Resistance
All factors that act to limit the growth of a population.
Limiting factors
Light, water, living space, nutrients, exposure to too many competitors, predators, or infectious diseases.
Logistic Growth
(S shaped) rapid exponential growth, then a steady decrease in population growth with time until the population size levels off.
When does logistic growth occur?
As the population faces environmental resistance and approaches the carrying capacity of its environment.
Reproductive timelag
Period needed for the birth rate to fall and the death rate to rise in response to over resource consumption.
How can species increase their carrying capacity?
By developing adaptive traits through natural selection that reduce environmental resistance to their population growth.
How have we extended the earths carrying capacity?
1)Increased food production
2)Used large amounts of energy and matter resources.
Population density
The # of individuals in a population found in a particular are or volume.
Density dependent population controls:
Competition for resources, predation, parasitism, and infectious disease.
Higher populations can
1)Help reproducers find mates
2)Increased population for food, living space,water, sunlight, and other resources.
3)Shield members from predators in bug groups bur become vulnerable as a big group to humans.
4)Increase the transmission if infectious disease.
four types of population size:
Stable:Population size fluctuates a little above and below its carrying capacity.
Irrupt:Population growth occasionally explodes to a high peak and then crashes to a more stable lower level.
Cyclic:Rise and fall
Irregular:Irregular behavior in either changes in population, no recurring pattern.
Asexual reproduction
Offspring are generally exact genetic copies of a single parent. (clones)
Sexual reproduction
Mixes the genetic material of two individuals and produces offspring with combinations of genetic traits from each parent.
Disadvantages of sexual reproduction
1)Males do not give birth
2)Increased chance of genetic errors and deflects during the splitting and recombination of chromosomes
3)Courtship and mating rituals consume time and energy, can transmit diseases and can cause injuries on males for competing for partners.
Advantages of sexual reproduction
1)Greater genetic diversity in offspring
2)Males of some species can gather food for the female and the young and protect and help train the young.
R-Selected species
-Species with carrying capacity for a higher rate of population increase
-have many, small offspring and give them little or no parental care or protection.
K-Selected Species
-Fewer, larger offspring
-Develop inside mothers
-Cared for, protected by parents
-Do well in competitive conditions whether population size is near the carrying capacity of the environment.
Survivorship curve
Shows the percentages of the members of a population surviving at different ages.
What are the three types of survivorship curves
2)Early loss
3)Constant loss
Life table
Shows the projected life expectancy and probability of death for individuals at each stage of survivorship curve.