ExtinctionHow is it related to biodiversity?

Extinction• Biodiversity: the

variety of life on Earth.

• Evolutionary survival strategy

• Biodiversity has suffered some major setbacks during the past 500 million years.

History of Extinction SB Pg.216

Dinos175 MY

Humans1 MY

Extinction Due To:1.Climate Change2. Volcanic Eruption3. Meteor Impact

Biodiversity Recovery

• Process takes millions of years

• Recovery involves new species evolving and replacing old ones.

Background Extinction Rates

• Normal Background Extinction Rate: 10-25 species/year

• Current rate (SB p.217-218)• 50,000/year• 137/day• 6/hour

Rivet HypothesisDecreasing Biodiversity Little by Little

Cute Cuddlies vs. Stinky

Uglies

Importance of Preserving

Ecosystems• Trophic Pyramid

• What can happen if the top is damaged?

• What can happen if the bottom is damaged?

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

Resources Demo

Next Generations?

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.