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15 Cards in this Set

  • Front
  • Back
Populations tend to spread from one location to another.
May be passive or active.

Sometimes happens in response to limited resources.
Passive dispersal
Wind, water current, etc.
Active dispersal
Under control of organism: running, walking, swimming, flying.
Dispersal Specifics
May involve dispersal of emryos (seeds, spores, eggs), larval or juvenile life stages.
Effective ways to populate new regions or acquire resources.
Examples: dandelions; apple seeds; barnacle larvae.
Physical Dispersal barrier
Mountains, valleys, large bodies of water.
Habitat specificity and behavior dispersal barrier
Forest versus grassland inhabitants.
Climatic variation dispersal barrier
Arctic & Antarctica are similar but divided by tropical & temperate climate regions.
Different fauna at different poles.
Human dispersal
Few barriers limit human dispersal.
Space & water.
Earth’s Carrying Capacity
Based only on food = 7-8 billion people.
Human Population Growth
Agriculture & Inustrial Rev have fueled rapid pop expansion.
Global resource distribution
Food resources are not equally distributed across globe.
Wrong food.
Not enough food.
Ecological footprint
US residents have large footprint, but not big enough ecological capacity (resource deficit).
Mexico’s Population
Mexico has big growth rate due to much youth.