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Evolution of Biodiversity

Evolution of Biodiversity. Chapter 5. The Dung of the Devil. Why was the plant root people in China used to fight flu called the Dung of the Devil? What is the significance of this plant to us at this time? What was the original source of aspirin?

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Evolution of Biodiversity

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  1. Evolution of Biodiversity Chapter 5

  2. The Dung of the Devil • Why was the plant root people in China used to fight flu called the Dung of the Devil? • What is the significance of this plant to us at this time? • What was the original source of aspirin? • What percent of new drugs have their source in animals, plants or microbes?

  3. What is happening to the known or suspected sources of new drugs? Why is relocation of indigenous people a concern with respect to new natural drugs? Explain why the search for natural drugs is an argument for conserving Earth’s biodiversity.

  4. Define: • Ecosystem diversity • Mountain

  5. Define • Species diversity • Richness • Evenness • Genetic diversity • Value?

  6. How Many Species Live on Earth? • Define species: • The number of species in a given area is the most common measure of biodiversity. • Hard to estimate because: • 2 million named species • Current estimates are: • The group with the most species:

  7. What determines species diversity? • Where is species diversity the highest? • Measure the species richness and the species evenness. • Which community is more diverse?

  8. Allopatric Speciation • How we move from microevolution to macroevolution. • Allopatric • Geographic isolation • Reproductive isolation

  9. Allopatric Speciation

  10. Sympatric Speciation • Evolution of one species into two species when: • Process of polyploidy • Polyploidy • Occurrance • Accidently • Deliberate human actions

  11. Sympatric Speciation

  12. Pace of Evolution • Ability of a species to survive depends on: • Hundreds to millions of years. • Average global rate: • Rapid evolution: • Species with high genetic variation • Cichlid fishes of Lake Tanganyika. • The ability of a species to survive an environmental change depends on:

  13. 4 Factors for Species Survival • Rate of Environmental Change • Genetic Variation • Population Size • Generation Time

  14. Pace of Evolution by Artificial Selection • Can be incredibly fast. • GMO – genetically modified organisms • Description • Example

  15. Environmental Conditions • Each species or community has different needs. • Range of Tolerance: • As conditions move further away from the ideal:

  16. Fundamental vs. Realized Niche • Habitat: • Niche: • Fundamental Niche • Abiotic factors: • Biotic factors: • Realized Niche • Distribution • Areas of the world in which the species lives.

  17. Law of Tolerance • The distribution of a species in an ecosystem is determined by the abiotic factors within range tolerated by the species. • Add to the Laws page of notebook

  18. Limiting Factors • Condition(s) that affect a population’s ability to survive. • Too much or too little of any abiotic factor can limit or prevent growth even if all other factors are in the range of tolerance. • Aquatic biomes limiting factors: • Terrestrial biomes limiting factors:

  19. Generalist/Specialist Species • Generalists– wide niche • Niche characteristics: • Specialists – narrow niche • Niche characteristics:

  20. Cockroaches: Nature’s Ultimate Survivors • 350 million years old • 3,500 different species • Ultimate generalist • Live for a month on one drop of water. • Live for a month without food. • Can withstand massive amounts of radiation. • One species can live after being frozen for 48 hours.

  21. Giant Panda • Loss of habitat due to: • Specialist characteristics • Diet - Bamboo • Nutrient poor and they prefer the young sprouts which are even lower in nutrients. • Must eat from ¼ to ½ of their weight/day. • Defecate 40 times a day. • Therefore they must minimize energy expenditures. • Even their cubs are very small and undeveloped at birth.

  22. Generalist and Specialist Species • If conditions change quickly: • Better to be a generalist. • Because: • If conditions are steady: • Better to be a specialist. • Because:

  23. Environmental Change • Environmental change can affect species distributions. • Check sediments of modern lakes:

  24. Predicting Future Species Distributions • Global Climate change predictions: • North American trees are expected to have more northerly distributions. • Species vary in their ability to adapt or physically move: • Adaptation depends on: • Movement depends on:

  25. Environmental Change and Species Extinctions • When conditions change, species can: • Average life span of a species ranges from: • 99% of the species that have ever lived on earth are now extinct. • Problems for the polar bear: • Other types of problems: • Other species in the area that the moving species is not able to compete against successfully. • Change so rapid that adaptation is not possible.

  26. Fossil Record • Most organisms die and decompose with their elements then recycled. • Some organisms are preserved in fossils – remains of organisms preserved in rock, mud, sediment. • Fossil process: • Oldest fossils:

  27. 5 Global Mass Extinctions • Mass Extinction: At end of Cretaceous period 251 million years ago – greatest mass extinction

  28. 6th Mass Extinction • Think HIPPCO • Anthropogenic • 2- 25 % of species going extinct by 2020.

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