1. Human Activities & their Impacts on the Earth’s Environment
4.2

2. Humans Early History Began as hunter-gatherers
No different from other animals
In harmony with environment around them
Omnivores—top of the food chain
Primary: hunting, fishing, farming, mining, & forestry
Depend on natural resources obtained from land or sea.

4. Domesticating Animals lead to…
Control the sources of their own food supply
Farm output increased and yielded a food surplus people could master other skills
 Secondary: manufacturing goods (changing) came after raw materials (natural resource) were obtained.
Tertiary: the need for services grew from the other two.
Service sector workers: administration, public services, health care, transport and communications, selling goods, leisure, and tourism

5. Genetic Engineering & GM Crops
Genetic Engineering- process of altering the genetic composition of an organism by modifying its own genes or introducing genes from a different species.
Selective breeding vs. genetic engineering
Involves transfer between unrelated species
Biotechnology- use of living organisms or biological processes for industrial, agricultural, or medical purposes.
Genetically Modified Crops-

6. Genetically Modified Foods
PRO (Scientists)
CON (Environmentalist)
“sowing the seeds of a better future”
Saving millions from dying
Climate change
Pests
Lack of food for population growth
Second Green Revolution is to tinker with genes
“Genetic scientist are altering life itself— artificially modifying genes to produce plants and animals which could never have evolved naturally”
Creation of super weeds that have no natural controls
Replace existing plants and animals further reduction biodiversity
Increase in food output has not increased with GM foods like biotech companies claim
GM foods are being used in food-rich countries because it will only be made for money

7. Extinction Natural All species become extinct
Mass Extinction-extinction of many species in a relatively short period of geologic time
3-5 mass extinctions on earth so far
-Human activity has ACCELERATED extinctions

8. Extinction rates are RISING:
Projected growth of human population and its growing use of resources per person
Human influence on climate change
Current & projected rates are much higher in biodiversity hotspots
Tropical rainforests, estuaries, tropical coral reefs, and wetlands
Eliminating, degrading, fragmenting, & simplifying many biological diverse environments that serve as potential colonization sites for new species.

9. 4 Reasons WHY we should CARE about EXTINCTION
World species are a vital part of the earth’s life support system
Contribute to economic services
Will take double the time (5-10 million years) for natural speciation
Ethical responsibility that each wild species has the right to live

10. Ecological Smoke Alarms
Endangered Species
Threatened Species
So few individual survivors that the species could soon become extinct
Sumatran tiger, panda bear, Florida panther d/
Still has enough individuals to survive in the short term
Polar bear ch

11. Most important, Direct causes of extinction, resulting from human activities: HIPPCO
--Habitat Destruction, degradation, & fragmentation
--Invasive Species
--Population growth & increasing use of resources
--Pollution
--Climate Change
--Overexploitation H I P C O

12. Habitat Fragmentation
Large, intact area of habitat
is divided into smaller, isolated patches or “habitat islands.”
National parks & reserves

14. Invasive Species Prevention of Invasive Species:
Fund massive research program to identify possible invaders, etc.
Increase ground surveys & Satellite observations to track invasive species and develop better models for predicting how they will spread
Establish international treaties that ban harmful invader species
Require Cargo ships to discharge their ballast water or sterilize water, pump nitrogen into water
Educate the public about the effects of releasing exotic plants & animals
Cause economic and ecological damage that average at least $162,000 an hour, worldwide
Ex: Kudzu Vine (Pro/con?)

15. Tourism