1. 19.1 Ecology The study of interactions between organisms and the living and nonliving components of their environment. Oikos = house Logy = study of

2. Exploding Human Population The worlds population since 1930 has tripled from 2 billion to 6 billion in 1999. Projections estimate by 2050 a population of 7.8 and 12 billion.

3. The Sixth Mass Extinction Due to this exploding human population scientists estimate that 1/5 of the species that exist today may disappear in the next century. Scientist have found evidence of five previous mass extinctions. Ex. Ice ages, dinosaurs dying out.

4. Thinning ozone The ozone layer protects organisms from ultraviolet (UV) light. Due to the production of CFC’s (ChloroFloroCarbons) there is now a hole in the ozone over Antarctica

6. Climate Changes The Greenhouse effect is when gasses trap solar radiation in the atmosphere of the earth. If this effect is too strong it can become too hot If the effect is too weak it can become too cold.

8. Levels of Organization Biosphere Ecosystem Community Population Organism

9. Biosphere All organisms live in the biosphere (earth)

10. Ecosystem The biosphere is made of many ecosystems Ecosystems include the living and non living things found in a particular place.

11. Community, Population, and Organism. All these are living things. Community is all the organisms living and interacting in an area Populations include all the organisms of one type of species Organisms are individuals

12. Key theme in Ecology No organism is isolated. There is an interconnectedness of all organisms

13. Disturbances in Ecosystems Due to interconnectedness if one species dies out this can affect other organisms.