1. Chapter 6 Extinction How is it related to biodiversity?

2. Sacred Balance Extinction Crisis  SB (p. 216-219) Suzuki states “Our tenuous inferences about life in the past are based on fossil remains suggesting that species expand in number and complexity and then are suddenly reduced through successive spasms of extinction.” What evidence does Suzuki give to support this statement?

3. Extinction  Biodiversity: the variety of life on Earth.  Evolutionary survival strategy.  Biodiversity has suffered some major setbacks during the past 500 million years.

4. History of Extinction SB Pg.216 Dinos 175 MY Humans 1 MY Extinction Due To: 1.Climate Change 2. Volcanic Eruption 3. Meteor Impact

5. Biodiversity Recovery  Process takes millions of years  Recovery involves new species evolving and replacing old ones.

6. How many species are there in the world?  Approximately 1.4 million species have been named.  Of these more than half (751,000) are insects.  About 248,000 species of plants have been described  281,000 non-insect animals (fish, reptiles, birds, mammals, crabs, starfish, sea urchins, jellyfish, worms, etc.).  Relatively few Protists (57,700), fungi (69,000) and prokaryotes (4,800) have been named.

7. Background Extinction Rates  Normal Background Extinction Rate: 10-25 species/year  Current rate (SB p.217-218)  50,000/year  137/day  6/hour

8. Rivet Hypothesis  Rivet hypothesis suggests that just as a plane can lose the odd rivet an ecosystem may withstand the loss of one or a few species without any discernable effect.  However, like a plane that loses one rivet too many, it may then suddenly collapse.

9. Cute Cuddlies vs. Stinky Uglies

10. Importance of Preserving Ecosystems  Trophic Pyramid  What can happen if the top is damaged?  What can happen if the bottom is damaged?

11. Sacred Balance p. 217  “We are fortunate to have evolved when biological diversity has been at the greatest level ever achieved. Succeeding human generations will not be as fortunate: the current extinction crisis is without precedent —never before has a single species been responsible for such a massive loss of diversity”  Relationship between population and resources

12. Resources Demo Next Generations?

13. Man vs. Nature: Ikei Island  Industrialization of Japan causes its coast to become polluted.  Fish migrate to Ikei Island to cleaner waters  Dolphins follow fish  Fish prices increase because there is a decrease in the coastal fish population due to pollution.  Fishermen compete with eachother employing new technologies (hand held lines vs. gill nets) because fish prices increase further decreasing fish population (overfishing)  Fishermen compete with dolphins for fish.  Blame dolphins for low catch rates instead of pollution and overfishing caused by humans.  Herd and kill dolphins to thin their numbers.