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Demographics - Coggle Diagram
Demographics
Human Population Growth
Invention of Agriculture 11,000 yrs ago = dependable food supply
Fertilizers increase crop yields
Pastuerize food/ drink
Protect/ clean drinking water
Mid-18th C: Harness fossil fuel energy
Medicine
Cleanliness
8 billion now
Est. 9 billion by 2050
Fertility rate
Total
Replacement
Age structure
Reproductive base
Demograpic transition model
Population Size
Per capita growth rate
Zero population growth
Exponential growth
J Shaped
Logistic growth
Biotic potential: Maximum possible growth rate
Density-dependent limiting factors
Carrying capacity (K)
Intraspecific competition
Life history
Cohort
Death: Survivorship curve
Type I: Convex
Low death rate until late life
Large mammals
Type II: Diagonal
Death rate does not vary much with age
Lizards, small mammals, large burs
Type III: Concave
Death rate peaks early in life
Marine animals, plants
Reproduction Selection Types
r-selection: opportunistic
Maximize per capita growth rate
small body, short generation, often type III survivorship
K-selection: equilibrial
Maximize adaptive trait advantage
near carrying capacity (K)
Large body; long generation; often type I survivorship
Mixed r- and K- traits
one shot reproductive opportunity
Atlantic eels; Pacific salmon
Population Density
Ecology
Population Distribution
Emigration
Immigration
Density-independent limiting factors
Ecological Footprint