APES 3.8 Human Population Dynamics

Societal Factors Effecting Human Populations

  • Some common factors that affect whether a population is growing or declining include:
    • Birth rates
    • Death rates
    • Education
    • Infant mortality
    • Age of marriage
    • Early age of marriage speeds population growth; usually correlates with early age of first pregnancy
    • Nutrition

Limits

  • Even human populations experience Carrying Capacity
  • Thomas Malthus proposed that all populations have a limit, and that the human population will run out of food, causing a huge famine and mass-dying
    • He, however, lived before industrialization and did not see many of the technological advances we have today

Types of Limits

Density-Independent
  • It does not matter how many people there are and how closely they live, these factors will affect them either way
  • Storms
  • Fires
  • Heat waves
  • Drought
Density-Dependent
  • Their lethality rely on how many people there are and how closely they live
  • Disease transmission
  • Territory size
  • Food availability
  • Access to clean air and water

Environmental Problems

  • Human populations deal with many environmental issues
  • Many of the density independent factors from before apply here
  • Natural disasters, for example, cause high density areas to suffer a drop in population
    • This is because of damage to homes, economic losses, and better opportunities being taken up in the aftermath

Rule of 70 and Doubling Time

  • Doubling time is the amount of time a population will take to double, assuming the population growth rate stays constant
  • The equation used is (70/rate = Doubling time)
  • For this calculation, r will stay in percentage form
    • Meaning you should not convert 1.85% into .0185