Lecture 20 Flashcards
Human Demography
study of the characteristics of human populations, such as size, growth, density, distribution, and vital statistics
3 Demographic Transitions
- old people outnumber younger people
- urban people outnumber rural people
- by 2050 there will be 6x the number of people in the lesser developed world
Biodiversity
variety of life on Earth at all its levels, from genes to ecosystems and the ecological and evolutionary processes that sustain it
Types of Biodiversity
- genetic Variation
- community diversity
- ecosystem diversity
- ecological processes
- evolutionary processes, natural selection
- geography of this variation
Where biodiversity is
intact habitat of biodiversity hotspots now comprises only 1.4% of the earths surface
Extinction
- over 99% of species that have ever existed have already gone extinct
- we are experiencing an extremely high rate of extinction
Importance of biodiversity:
- intrinsic value
2. antropocentric values
Intrinsic Values
-all species need diversity to survive
Antropocentric Values
Direct Value: goods-food, fuel, etc
Passive Value: services - oxygen and carbon cycling, pollination, decomposition, nitrogen fixation, etc
Potential Value: information
Psycho-Spiritual/aesthetic value
Pros of Urbanization
- Concentration of Impact
- Economies of scale
- Abandonment of marginally productive lands
Cons of Urbanization
- Concentration of impact
2. strains capacity