Population Dynamics
What are the three key factors that affect population size?
Birth rate, death rate, migration
What are the three types of survivorship curves?
Type I, Type II, Type III
What happens to a population when it exceeds its carrying capacity?
It declines due to resource scarcity
What is the formula for population change?
(Births + Immigration) - (Deaths + Emigration)
What does a wide base in an age structure diagram indicate?
Rapid population growth
What type of growth shows a population increasing rapidly without limits?
Exponential growth
Which curve represents organisms that produce few offspring but care for them?
Type I
Define biotic potential.
BONUS: Explain one social or cultural factor that impacts fertility rate.
The maximum reproductive capacity of a population under ideal conditions
BONUS: 300 Points
Example: education access for women lowers TFR
Which stage in the demographic transition shows the fastest population growth?
BONUS: How might agriculture increase carrying capacity artificially?
Stage 2
BONUS: (100 POINTS)
More food production allows support for larger populations
What does a top-heavy age pyramid suggest about a population?
Aging population, low birth rates
What term describes a maximum population that an environment can sustainably support?
Carrying capacity
Compare r-selected and K-selected species using 2 traits each.
BONUS: How might a survivorship curve shift due to habitat destruction?
r: many offspring, little care; K: few offspring, more parental care
BONUS: 100 POINTS
Toward Type III: more infant mortality
What is the significance of the logistic growth model?
Shows population growth slowing as it nears carrying capacity
What are two major reasons for the global human population increase in the last 200 years?
Industrial revolution, medical advances
Name 2 factors used to calculate doubling time.
Growth rate and Rule of 70
A population has a birth rate of 20/1000 and death rate of 8/1000. What is the growth rate?
1.2%
What is one advantage of being a Type III species in an unstable environment?
Produces many offspring; high chance that some survive
What are environmental resistance factors?
Factors that limit population growth (e.g., disease, food scarcity)
Define Total Fertility Rate (TFR).
Average number of children a woman will have in her lifetime
Calculate doubling time for a country with a 2% growth rate.
BONUS: Why might a country implement pro-natalist policies?
70 / 2 = 35 years
BONUS: 250 POINTS
To encourage higher birth rates and balance aging population
What are density-dependent and density-independent limiting factors? Give one example of each.
BONUS: Describe a real-world example where a species exceeded carrying capacity and what followed.
Dependent: disease; Independent: natural disaster
BONUS: 200 points
Example: Deer in predator-free area → resource depletion → die-off
Give an example species for each survivorship type.
I: humans
II: birds
III: fish/frogs
Why are carrying capacities hard to determine in human populations?
Technology and trade constantly shift our resource use
What is replacement-level fertility, and why is it higher in developing countries?
~2.1; higher in developing countries due to higher infant mortality
How can age structure affect a country's economy?
Large youth population increases strain on education; aging = healthcare strain