population dynamics

What region has the greatest population growth momentum (greatest potential for growth)? What percentage of the population of this region is under age 15?

- Africa - 40% of the population is under 15

Give, in order, the three largest countries by population, and their populations. When is India expected to surpass China? What country is expected to pass the U.S. in 2049 and move into 3rd place?

- India (1.43 billion), China (1.42 billion), U.S. (314 million) - India is expected to pass the U.S. in 2023 - Nigeria is expected to pass the U.S.

What country has the world's longest life expectancy? What is its fertility rate? This country has the lowest percentage of what age group? What is discouraged in this country, and what are the implications of this?

- Japan - low fertility rate of 1.4 - lowest percentage of young people - discourages immigration - does not have enough young people to work and support their aged population (work force shrinking )

What is age structure? 2% of U.S. males are between the age of 70-74, and 2% of females are in this same age group. Given the U.S. population is 325 million, how many total people are in this age group?

- age structure: the distribution of people in a population by age - 325 million x 0.04 = 13 million

Body size

K: large body size in adults R: small body size in adults

size of offspring

K: larger offspring R: small offspring

stable

japan, italy, greece

What technique can be used to estimate the size of a population? Briefly explain how this technique works.

mark-recapture method: scientists capture, mark, and release a random sample of individuals in a population, these marked individuals spend time living normally with their population, scientists collect a second sample and note how many are marked

As population density increases, what do density-dependent factors do to population growth? How? These factors tend to keep a population at or near what level?

- as population density increases, density dependent factors slow population growth by causing an increase in death rate and/or decreasing birth rate - these factors tend to keep a population at or near the carrying capacity

What are the birth and death rates like during the 1st stage? What is the population size and growth rate during this stage?

- birth and death rates are both high - population size stays low - growth rate is slow

What does low fertility rate usually lead to? In what region is this most evident?

- low fertility rate lead to larger elderly population - evident in Europe

What may be the single most important factor affecting high fertility rates in many societies? Which sex is more illiterate? Why?

- low status of women in many societies - women are more illiterate than men because women are kept at home to work instead of going to school

what did Malthus say about the human growth rate? What did he say the result would be?

- malthus said the human growth rate could exceed the carrying capacity of the Earth (supply of water, food, etc.) - the result would be disease, war, and famine

In LDCs, many people have large numbers of children in order to do what for the family? What is the problem found in countries like India? How can religious values influence TFR?

- many people have large numbers of children in order to work to support their families and support their parents when they become old - High value placed on male children in places like India - religious values influence TFR: catholics have a higher TFR than Protestants and Jews

Culture and society influence individual behaviors regarding fertility rate in what ways? Why is marrying early a problem? Why is high infant mortality a problem?

- marriage age is traditionally young in many places - marrying early is a problem because it means more babies - high infant mortality leads couples to be expected to have a large number of children

What is the most densely populated country? What is the most densely populated LDC?

- mostly densely populated: monaco - most densely populated LDC: Bangladesh

What are two characteristics of women with more education? What will empowering women with education and jobs do?

- women with more education: marry later and have fewer children - empowering women with education and jobs will reduce TFR

What are 4 factors that can influence the size of r? What are these factors collectively called?

Factors are called life history characteristics: - age at which reproduction begins - fraction of life span during which an individual can reproduce - # of reproductive episodes per lifetime - # of offspring produced during each reproductive episode

declining

Germany, Bulgaria, Russia

expanding rapidly

Guatemala, Nigeria, Saudi Arabia

homeostatic ability

K: High homeostatic ability R: Low homeostatic ability

conditions adapted to

K: adapted to stable conditions R: adapted to unstable conditions

Energy Use

K: energy used for growth and maintenance R: energy used for reproduction

Young per reproductive episode

K: few offspring per reproductive episode R: many offspring per reproductive episode

competitive ability

K: high ability to compete R: low ability to compete

successional stage

K: late successional species R: Early successional species

type of population growth

K: logistical growth R: exponential growth

life span

K: long life span R: short life span

mortality rate

K: low mortality rate R: High mortality rate

time required to mature

K: mature later in life R: mature early in life

level of parental care

K: parental care often extensive R: no parental care

Number of reproductive episode

K: several reproductive episodes during life R: usually one offspring per reproductive episode

type of niche

K: specialist niche R: generalist niche

what is the formula for calculating population size

N = sn/x (s is the number of individuals marked in the first step, n is the amount captured in the second sample, and x is how many of the second sample are marked)

What 2 types of reproductive strategies exist? Give two example of species that follow each type.

the two types of reproductive strategies are r and k strategist r strategist ex: dandelion and mosquito k strategist ex: coconut palm and elephant

When did the population reach 1 billion? How long did this take? How long did it take for our population to go from 6 to 7 billion?

- human population reached 1 billion in 1804 - this took thousands of years - it took 12 yrs

Environmental resistance puts an end to ______________ growth, causing population growth to level off at the _______________ of the environment.

exponential; carrying capacity

What are the 2 types of factors that affect population size? What are density-dependent factors? What are 4 examples of this type of factor?

- 2 factors: density-dependent and density-independent - density dependent factors are factors whose effects change as the population density changes - 4 examples: competition, lemmings emigrate when it gets too crowded, diseases and parasites are more easily transmitted between individuals when the population density is high, as population density increases predators are more likely to find an individual of given prey species, as population density increases the amount of desirable habitat/living space decreases

What are 3 basic needs that are difficult to meet in developing countries? What are the problems associated with overpopulation?

- 3 basic needs: balanced diet, clean water, and decent shelter - problems: environmental degradation, hunger, persistent poverty, economic stagnation, urban deterioration, and health issues

What is the name of the 3rd demographic stage? What are the birth and death rates like during the 3rd stage? What causes the birth rate to decrease? What does this do to population growth?

- 3rd stage is called the industrial stage - birth rate and death rate both decrease - birth rate decreases because of improved food production, health, and education - population growth still increases (slower) because the birth rate is still higher than the death rate

Demographer Frank Notestein recognized that human populations go through how many demographic stages over time? What is the name of the 1st demographic stage?

- 4 demographic stages over time - 1st stage is known as the preindustrial stage

What percentage of pregnancies are unplanned in LDCs? How many end in abortion?

- 42% of pregnancies in LDCs are unplanned - 26% end in abortion

Women account for what percentage of hours worked worldwide? What percentage of the income and land ownership goes to women?

- 66% of all hours worked - 10% of the worlds income and 2% of land goes to women

What are 4 factors that cause populations to change in size over time? Each one of these factors should be expressed in terms of how many individuals per year?

- Birthrate: expressed as # of births per 1000 people per yr - Deathrate: expressed as # of deaths per 1000 people per year - Immigration: expressed as # of immigrants per 1000 people per year - Emigration: expressed as # of emigrants per 1000 people per year

What is the oldest country, in terms of age of the population? Why is this a problem for this country? What is this country running out of? How are they "solving" this problem?

- Japan is the oldest - this is a problem because as population ages, there are fewer working adults to pay taxes to support an increasingly elderly population - Japan is running out of workers (relying on more robots for many jobs) - they are discouraging immigration

What is total fertility rate (TFR)? What is the current worldwide TFR? What was it for LDCs in 1970? Because our TFR is greater than replacement-level fertility, what will our population continue to do?

- TFR: the average number of children born to the women in a population - worldwide tfr: 2.4 - TFR in LDCs in 1970 6.1 - our population will continue to rise

What is the shape of the age structure diagram for the U.S.? What does this mean for our future population?

- U.S. age structure diagram is shaped with more pre-reproductive and reproductive people than post (older people) - slow population growth

What is a life table? What is a cohort? What is survivorship?

- a life table is an age specific summary of the survival pattern of a population - a cohort is a group of individuals of the same age - survivorship is the proportion of individuals surviving at each age in a given time period

What country has the largest population? What did this country do in 1979 to solve their population problem? What incentives were given to promote this policy?

- china - they created a penalty for 2nd child and incentives to promote late marriages and one-child families

What is the current annual growth rate of the world population? When did it peak? At what value did it peak? When is zero population growth expected to occur?

- current annual growth rate of the world population is 0.88% per year - it peaked at 2.19% in 1963 - zero population growth is expected to occur when sometime near the end of the 21st century

In what countries is the population declining? Which country is declining most? Why?

- declining in Germany, Russia, and Bulgeria - bulgeria because of its high death rate, low birth rate, high abortion rate, and high emigration rate

What is the demographic transition? During what stage does it occur? What is the population growth rate during this stage? What happens to the total fertility rate during the demographic transition? What are the 2 biggest contributors to the dramatic increase in the size of the human population during the last century?

- demographic transition: transition from high birth and death rates during the preindustrial stage to low birth and death rates during the industrial/postindustrial stage as a country develops an industrialized economic system - occurs during the transitional and industrial stages - greatest rate of growth - TFR decreases - 2 biggest contributors: industrial revolution and modern medicine

What is demography? What is demographics? What is the current human population?

- demography: the science of human population structure and growth - demographics: the statistical data of a population - current human population is 8.1 billion

What are density-dependent factors? What are some examples? Density-dependent and independent factors cause what type of population growth to ensue?

- density independent factors are factors that affect population size, but are unrelated to population density- affect a similar proportion of individuals regardless of population density - density dependent and independent factors cause a logistical growth

What is environmental resistance? How does it affect the growth of populations? Environmental resistance includes what limiting factors?

- environmental resistance: the combination of all factors that act to limit the growth of a population - environmental resistance limits the growth of populations - limiting factors (food/water shortages, lack of shelter, space, predation, competition, disease)

What is the shape of the age structure diagram for Ethiopia and Guatemala? What does this indicate about its future population? What type of momentum exists in this population? What does this mean?

- ethiopia and guatemala shaped like a pyramid - this indicates that they have a high probability of future growth because the largest percent of the population is in the pre-reproductive ages (0-14) - positive population momentum (the greater the proportion of very young individuals, the greater the population momentum) - means that when all of the children mature, they will be the parents of the next generation, and this group of parents will be larger than the previous group

What type of growth are humans exhibiting? What is the shape of our growth curve?

- exponential growth - J shape curve

What has been a major factor in reducing the number of births worldwide? This has caused how large a drop in TFR in LDCs? What was the TFR in 1960 in LDCs, and what is it now?

- family planning - cause a drop of atleast 55% in TFR in LDCs - from 6.0 in 1960 to 2.6 in 2012

What is the shape of the age structure diagram for Italy? What does this mean for its future population?

- fewer preproductive and reproductive people than post (fewer young than old) - no growth or decline in growth

What country has the highest TFR, and what is its value? Why is the U.S. population still rising, even though we have dropped below replacement? What is the current U.S. TFR?

- highest TFR: Niger (6.7 children per woman) - the us population is still increasing because of immigration - current U.S TFR is 1.7

Why does Mexico have a huge potential for growth? What percentage of their population is under age 15? How did the Mexican government solve this problem? What happened to their TFR?

- huge potential for growth because of its young age structure - under 15: 29% - mexican government solved this problelm by imparting educational reform, family planning, and health care - TFR dropped from 6.7 in 1970 to 2.3 in 2011

What is the name of the 2nd demographic stage? What are the birth and death rates like during the 2nd stage? What is the population size and growth rate during this stage? What causes the death rate to decline? What causes the population to increase?

- name is transitional stage - high birth rate, decreased death rate - population size rapidly increases (fast growth rate) = death rate declines because of improved food supply, water supply, and health care that accompany the beginning of an industrial society - population increases because of the combination of high birth rate and lowered death rate

What was the peak value for U.S. TFR? When did this occur? When was the period of remarkably high fertility rates in the U.S.? What was this period known as?

- peak: 3.7; occurred in the late 1950s - the period of remarkably high fertility rates in the US lasted from 1946-1964 and was known as the Baby Boom

What was the penalty for violating the above policy? What was the fertility rate in 1970 compared to 1981? Why was this policy controversial? What is their TFR now?

- penalty included fines, sterilization, and surrendering of privileges - fertility rate went from 5.8 in 1970 to 2.1 in 1981 - this policy was controversial because of the social pressure to abort 2nd children and abort/kill female 1st children - TFR is now 1.7

How can the population doubling time be found? What is the population doubling time in years for a country with an annual growth rate of 5%? If this country has a population of 200 million, what will be its population in 42 years?

- population doubling time can be found by taking 70% and dividing by the annual growth rate - growth rate of 5%: 14yrs - 1200 million

Even if total fertility drops below replacement, why will the population continue to rise? What is this phenomenon called?

- population will continue to rise because the number of future parents alive has grown, and they have not yet reproduced - this phenomenon is called population momentum

What is the name of the 4th demographic stage? What are the birth and death rates like during the 4th stage? What are 3 characteristics of people in heavily industrialized countries? What causes the population to begin to decrease in size during this stage?

- postindustrial stage - low birth and death rates - 3 characteristics: better educated, more affluent, and tend to desire smaller families (take steps to limit family size) - population begins to decrease because birth rate at first equals but then falls below death rate

What is replacement-level fertility rate? What is its value for HDCs? LDCs? Why is it higher than 2.0? Why is it higher in LDCs?

- replacement-level fertility rate: the average number of children that a couple must produce to replace themselves - its value for HDCs is about 2.1 - LDCs: 2.5 - its higher than 2.0 because some children die before they reach reproductive age - higher in LDCs because of their lack of education and contraceptive resources

What are 4 advantages of having a clumped distribution?

- resource availability - individuals moving in groups have a better chance of encountering patches of resources - protection from predators - some predators have a better chance of getting a meal in a pack

What has allowed food production to keep pace with population growth? Why might Malthus eventually be right? What is our carrying capacity estimated to be?

- scientific advances have allowed food production to keep pace with population growth - malthus might eventually right because it is unknown if our increase in food production is sustainable - our carrying capacity is estimated to be anywhere from 4 billion to 16 billion- median around 10 billion)

What is the main reason why there has been such a large increase in population? What are 3 reasons? What has happened to the birth rate the last few years?

- the main reason for an increase in population is a decrease in death rate - 3 reasons: greater food production, better medical care, improvements in water quality and sanitation practices - birth rate has declined but this is still outweighed by the decrease in death rate

What will be the only area still growing in 2050? What is its current annual growth rate?

- the only area still growing in 2050 will be Africa - Its current annual growth rate is 2.4%

How much is the population currently increasing per year? What is the population expected to reach in 2050? What about 2100? What percentage of the people born between now and 2050 will be born in LDCs?

- the population is currently increasing abt 80 million per year - in 2050 estimated population

What is the shape of a logistic growth curve? What can happen if a population drastically overshoots the carrying capacity (K)? What is a population crash? What is this type of curve sometimes called? This type of curve is commonly observed in what type of populations?

- the shape of a logistic growth curve is an S-shape - if a population drastically overshoots the carrying capacity overshoot occurs, leading to a population crash - population crash: an abrupt decline from high to low population density - this type of curve is called a bust curve - bacterial cultures, zooplankton and other populations whose resources become exhausted

What are the 3 types of survivorship curves? You should be able to identify the type of survivorship from a graph of survivorship over time.

3 types of survivorship curves are type I, type II, and type III

What does the crustacean survivorship curve look like? Why?

The crustaocean survivorship curve is a "star-shaped" curve because they have a brief period of high mortality when they molt, followed by periods of lower mortality when their exoskeleton is hard

K selected species typically follow a

Type I or Type II curve

R selected species typically follow a

Type III curve

expanding slowly

United States, Australia, China

What is a population? What is population ecology?

a population is a group of individuals of the same species living in the same geographic area at the same time; population ecology is the study of populations and why their numbers change over time

What is carrying capacity? What is logistic growth? You should be able to label the carrying capacity on a logistic growth graph, as well as the places where the rate of growth is accelerating, remaining constant, or slowing down.

carrying capacity: the max number of individuals the environment can support indefinitely logistical growth: population growth which accelerates at the beginning (exponentially), but slows and approaches zero as the carrying capacity of the environment is reached

What are the 3 ways a population can be distributed? Which is the most common? Which is the least common?

clumped, uniform, and random; clumped is the most common and random is the least

type II

constant death rate, due to random events that cause death with little age bias; relatively rare ex: rodents and some lizards

Why do creosote bushes exhibit a uniform distribution? What do dandelions exhibit a random distribution?

creosote bushes practice allelopathy, releasing chemicals which inhibit the growth of plants around them, resulting in a uniform distribution; dandelions have seeds that are dispersed by wind and land in random locations

age structure diagram

diagram that shows number of males and females at each age from birth to death

What is exponential growth? What is the shape of the growth curve during exponential growth?

exponential growth is population growth under ideal conditions, in which members of the population have access to reproduce at their biotic potential

What is food security? How many people lack it? What are the effects of chronic hunger? How can the food problem be solved?

food security is the condition in which people do not live in hunger or fear of starvation - more than 1 billion people lack it - effects of chronic hunger: weakens immune system, illness and diseases including malaria, measles, diarrhea, and acute respiratory illness - food problem can be solved by controlling population growth, promoting economic development of LDCs, providing access to food and land resources to those who live in areas without them

type III

high death rate for young, but low death rate once you survive to a particular age; many offspring; little parental care ex: marine invertebrates such as oysters and snails

What does the overall shape of an age structure diagram indicate about a population?

indicates the population growth rate, whether the population is increasing, stable, or decreasing

What is the intrinsic rate of increase of a population? What is it also sometimes called?

intrinsic rate: the rate at which a population would grow if it had unlimited resources (max reproductive rate); it is also called its biotic potential

In general, large organisms have what type of values for r? What about small organisms?

large organisms typically have small r values; small organisms have large r values

During exponential growth, the ____________ the population gets, the _____________ it grows. What are some examples of organisms whose populations grow exponentially?

larger; faster bacteria is an example of organisms whose populations grow exponentially

type I

low death rate in early and middle life, high death rate late in life; few offspring; good parental care ex: humans and elephants

What is the equation for calculating the growth rate of a population that takes into account all 4 factors that can cause the population to change over time?

r = (b-d) + (i-e)

What is the simplified equation for growth rate, taking into account only birth and death rates? How is growth rate normally expressed?

r = b - d - growth rate is normally expressed as a decimal or percent per year