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Evolutionary biology theory
Theory claiming that in the animal kingdom, pregnant females when faced by severe stressors preferentially abort frail male fetuses.
Composition
The distribution of the population in accordance with the intersecting characteristics of age and sex.
Fertility
Shifts in age composition are caused by changes in ______ (mostly) and mortality.
Females
______ live longer than males.
Sex ratio
Numerical balance between males and females in a population.
Aging transition
Societies pass from an initially young to an eventual aging structure.
Gross reproduction rate (GRR)
Measures the average number of daughters born to a women, given a prevailing schedule of age- specific fertility rates.
Life expectancy at birth
Measure of survival determined by a population's age-specific mortality rates.
Stationary age structure
Structure in which annual rates of natural increase remain exactly zero indefinitely due to equal numbers of births and deaths annually.
Stable population
Structure with very low constant rates of natural growth.
Net reproduction rate (NRR)
Measure of a population reproductivity.
Ergodic property of populations
The tendency for populations to eventually "forget "their initial age distributions.
Hormone, conception
Sex-ratio at birth is controlled by parental ________ levels at the time of ______
Age distribution
Those under 15 (youth), those aged 15-64 (working age), and those aged 65+ (post-retirement)
Total dependency ratio
The ratio of youth + old-age dependents ÷ working-age population
Age-sex pyramid
A pictorial representation of the age and sex composition of the population
Median age
The age that divides the distribution in half (half the population is above the median and the other half is below)
Intrinsic rate of natural increase
The difference between the intrinsic birth rate and the intrinsic death rate
Intrinsic birth rate
Rate at which mothers bear their daughters in a stable population, determined by a set of constant age-specific birth rates
Intrinsic death rate
Death rate in a stable population, determined by a set of constant age-specific death rates
100 years
Time it takes for a populations age structure to change completely
Population momentum
M = the size of the stationary population ÷ size of the initial population
Increase
When M is greater than 1, there is a population
Momentum
When M =1, there is no ________
Decline
When M is below1, there is a population _________
Primary sex ratio
Ratio of males to females at conception
Secondary sex ratio
Ratio of males to females at birth
Tertiary sex ratio
Ratio of males to females at birth beyond infancy
Males
______ are at greater risk of death than females throughout the entire lifecycle
103-107
Normal range of sex-ratio: - boys born for 100 girls
Low, high
High sex ratio for black and white populations (more men than women) meant _____ levels of family disruption and ______ rates of violent crime
Low, high
Low sex ratio (more women than men) meant ______ rates of violent crime and ______ levels of family disruption
Advantage
Women have a survival ______ over men
Workers, labor
Total dependency ratio helps to obtain a measure of a society’s overall dependency on the _____, who must provide for those not in the _____ force
Dependents, workers
If the dependency ratio is greater than 100 = more _______ than _____ in the population
Workers, dependents
If the dependency ratio is below 100 = more ______ than _______ in the population
Youth, median
Populations with relatively large old-age components tend to have relatively small ______ components and have a relatively high _______ age
Bulge, baby boom
Canada has an urn-shaped pyramid because it has a _____ in middle. The largest segment of population is the ____ _____ generation
Better
The higher the life expectancy, the ______ survival probability
Fertility
Greater GRR = higher _______
Younger
Declining mortality makes the age distribution _____ because there are more young people + more births
Younger
When the mortality declines are in infancy/early childhood, there is a _____ population
Aging
When mortality declines are in the ages 45+ such as in advanced societies nowadays, it is an ______ population
Different, identical
2 populations with ______ age structures will converge to ________ age compositions if they have identical age-specific birth and death rates over 70 years or more
115-130
Human sex ratio at conception is - males for every 100 females
Age
All 3 key demographic processes are dependent on ____
Sex, gender
All 3 key demographic processes are related to ____ and _____
Dependency
We use the age distribution to get a sense of the economic ________ burden in a given society
Negligible, minor
The effects of migration on age-sex structure are ______ since in large national populations, any amount of migration will only have a _____ impact
100
The sex ratio should be close to ____ males per 100 females
Abortion
More male than female fetuses are lost to spontaneous ______ or stillbirth
Note 
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