Unit 1 Populations Test Flashcards
Birth rate
of births year/ total population x 100
Population change
births + immigration – deaths + emigration
Death rate
of deaths per year/ total population x 100
Zero population growth (ZPG)
BR=DR
crude birth rate
of births per year/ 1000 people x 100
crude death rate
of deaths per year/ 1000 people x 100
crude infant mortality rate/child mortality rate
of deaths of infants or children/ 1000 live births x 100
Countries that are “developing” tend to have high infant and child mortality rates because of..
Inadequate access to food, clean water, and health care.
Replacement level fertility
the fertility rate required for the population to remain a constant size = 2.1
Expanding rapidly
a.k.a “the pyramid shaped” diagram
The pre-reproductive age group represents the greatest % of the population (lots of kids)
The TFR is high BUT these kids are not surviving to adulthood
Exponential growth will take place
Age structure diagrams
Pre-reproductive (0-14 years)
Reproductive (15-44 kids)
Post reproductive (45 and up)
Expanding slowly
The base is less wide on the triangle so fewer people are born but more people live longer. The pre-reproductive group still represents the largest proportion of the population (growth is slower than pyramid)
Stable
A.k.a the “column” diagram
The proportions of each level remain constant.
Replacement level fertility is 2.1
ex. Sweden, Norway, Finland
Declining
A.k.a the “inverted pyramid” The base is smaller than the top which means more people are dying and less are being born. Post-reproductive age group is the largest. Birth rate below replacement level fertility rate (ex. Japan)
Stage 1: Pre-industrial phase
Birth rate and death rate are very high and equal to each other
Total population remains constant (ZPG)
Currently, there is no country found in this stage
Stage 2: Transitional
BR stays high and DR drops dramatically
Total population grows exponentially because of…
Improved access to clean water, food, and healthcare
LESS PEOPLE ARE DYING
Stage 3: Industrial
BR starts to decline
DR continues to drop, but at a slower rate
Total population continues to grow, but the rate slows down because of…
Women are attending school for longer and they now play a role in society by having jobs. Also, children are not needed for labor.
TFR DECLINES
Stage 4: Post- industrial
BR & DR are at their lowest points and equal to one another
Total population approaches ZPG
Higher proportion of post-productive age cohort = less workers and less kids
Thomas Malthus
(1768-1834)
Economist, mathematician, and known as a founder of population studies in England
Density-dependent factors:
Food, water, shelter, competition, number of mates and predation
Density-independent factors:
climate change and natural disaster
POPULATION OSCILLATIONS
Some populations experience recurring cycles of overshoots and die-offs that lead to a pattern of oscillations around the carrying capacity of the environment.
K-selected species tend to exhibit which type of curve?
Type 1
r-selected species tend to exhibit which type of curve?
Type 3
“Generalists”
These are species that tend to be advantaged in habitats that are changing
(r-selected species)
“Specialists”
These are species that tend to be advantaged in habitats that remain constant
(k-selected species)
How should invasive species be classified - generalists or specialists? Why?
R since they thrive in changing habitats
How should endangered species be classified - generalists or specialists? Why?
K since they only thrive in constant habitats
Population Density:
of people/ area
Birth or Death Rates: *expressed as a %
BR= (# births/total population) * 100
DR= (# deaths/ total population) * 100
Population Growth Rate (r):
*expressed as a %
r=BR-DR
Annual Growth Rate (r):
(given crude BR & crude DR):
*expressed as a %
r = [CBR-CDR/1000] * 100
Don’t forget to include immigration and emigration (sometimes combined as “net migration”)
Doubling Time (dt)
Time (in years) it takes for a population to double (assuming that the growth rate, “r” remains constant)
Formula:
dt= 70/r
*keep “r” as a %
