Population Dynamics

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Population Dynamics
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Population dynamics

• The study of how populations change in size.
• Includes
• Growth rate
• Size
• Density
• Age structure

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Population change

• (Births Immigration) (Deaths Emigration)
• Uncontrolled growth is called exponential growth.
  
• Populations double every generation
• 1generation2
• 2nd Generation4
• J Curve

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Factors that control growth

• Biotic potential The ability or capacity to
  grow.
• Factors that change food sources-light
  nutrients-disease resistance-Ability to aquire
  food-K and R strategies Resources (land)
• Intrinsic rate of growth (r) the rate that a
  population would grow without any factors.
• R strategist have the fastest.
• Environmental Resistance- All of the factors that
  limit growth.

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Carrying capacity

• (K)
• The maximum number of individuals that may live
  in an area sustainably.
• If organisms exceed the carrying Capacity they
  tend to destroy other animals and eventually them
  selves.

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As populations reach the Carrying capacity

• As populations reach the Carrying capacity the
  environmental resistance increases thus slowing
  down population growth.

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The reality is..

• Populations tend to overshoot the carrying
  capacity.
• Going past the CC
• Leads to the death phase-population decline

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The amount of decline

• The amount a population exceeds a Carrying
  Capacity is equal to the amount of decline that
  population will have below the carrying capacity.

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Reproductive lag time

• The amount of time required for the birth rate to
  fall and the death rate to rise.

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Population Density

• An indicator of people per square mile
• A better indicator of over population.
• Takes into account the impact each person has on
  a specific area of land
• People/square miles

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Age structures

• Diagrams of populations broken down in to various
  ages.
• Broken down into gender.
• 3rd Tend to have larger amounts of children
• 1st older and mixed.
• 3rd More w die in middle life. Men die in old
  age..

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Demographic change

• As populations go from third world too first
  world the age structure will also change.

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Types of age structures

• Rapid growth
• 3rd world

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Slow growth
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Zero Growth

• Developed countries

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Negative population growth

• Developed worlds

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Assignment

• Page 309 questions 1-2 critical thinking.

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Ways to control population growth

• 1 Education not always work
• 2 Ath oritarian restrictions
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