Evolution

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Evolution

  1. 1. EvolutionEcology IMr. Nettles
  2. 2. Class Motto Discipline fuels character! Character builds hope! Hope assures your future!
  3. 3. Agenda- Wed., February 29, 2012b Warm-Upb Presentationsb Lecture: Evolutiono A-Plus
  4. 4. Today’s Objectives Define natural selection, evolution, adaptation, artificial selection, and resistance. Explain the process of evolution by natural selection. Articulate the concept of adaptation. Explain the steps by which a population of insects becomes resistant to pesticide.
  5. 5. Warm Up (Feb. 29)) List the four major levels of ecological organization in the correct order.t What is a population?t Why are habitats important?
  6. 6. “The Main Man”• Charles Darwin observed that organisms in a population differ slightly from each other in form, function, and behavior.• Darwin proposed that some individuals, because of certain traits, are more likely to survive and reproduce than other individuals.
  7. 7. Evolution by Natural Selection• Natural selection is the process by which individuals who are better adapted to their environment, survive and reproduce more successfully than less well adapted individuals do.• Evolution is a change in the characteristics of a population from one generation to the next.
  8. 8. Summary of Darwin’s Theory
  9. 9. “Survival of the Fittest” (nature selects)• Darwin thought that nature selects for certain traits, such as sharper claws, because organisms with these traits are more likely to survive.• Over time, the population includes a greater and greater proportion of organisms with the beneficial trait.• As the populations of a given species change, so does the species.
  10. 10. EvolutionEcology IMr. Nettles
  11. 11. Class Motto Discipline fuels character! Character builds hope! Hope assures your future!
  12. 12. Agenda- Thurs., March 1, 2012M Warm-Up (Standardized Test Ques.)d Lecture: Evolutiono Wrap-Upo Extra Credit Assignment • earn up to 35 points towards quiz grades
  13. 13. Today’s Objectives Define natural selection, evolution, adaptation, artificial selection, and resistance. Explain the process of evolution by natural selection. Articulate the concept of adaptation. Explain the steps by which a population of insects becomes resistant to pesticide.
  14. 14. Warm Up (Mar. 1) Standardized Test PrepMultiple Choice1. What is the term for the area where organisms live together with their physical environment? A. biome B. biosphere C. ecosystem D. population Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.
  15. 15. Warm Up (Mar. 1) Standardized Test PrepMultiple Choice1. What is the term for the area where organisms live together with their physical environment? A. biome B. biosphere C. ecosystem D. population Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.
  16. 16. Warm Up (Mar. 1) Standardized Test PrepMultiple Choice, continued2. Which of the following describes the theory of natural selection? F. Organisms with desired traits are selected for reproduction. G. Heredity determines which organisms will survive in their environment. H. Traits are developed in organisms in response to interaction with other organisms. I. Organisms with strong survival traits are more likely to pass the traits on in reproduction. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.
  17. 17. Warm Up (Mar. 1) Standardized Test PrepMultiple Choice, continued2. Which of the following describes the theory of natural selection? F. Organisms with desired traits are selected for reproduction. G. Heredity determines which organisms will survive in their environment. H. Traits are developed in organisms in response to interaction with other organisms. I. Organisms with strong survival traits are more likely to pass the traits on in reproduction. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.
  18. 18. Warm Up (Mar. 1) Standardized Test PrepMultiple Choice, continued3. What inherited trait increases an organism’s chance of survival and reproduction in a certain environment? A. adaptation B. characteristic C. evolution D. resistance Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.
  19. 19. Warm Up (Mar. 1) Standardized Test PrepMultiple Choice, continued3. What inherited trait increases an organism’s chance of survival and reproduction in a certain environment? A. adaptation B. characteristic C. evolution D. resistance Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.
  20. 20. “Survival of the Fittest” (nature selects)• An example of evolution is a population of deer that became isolated in a cold area.• Some of the deer had genes for thicker, warmer fur. These deer were more likely to survive, and their young with thick fur were more likely to survive to reproduce.• Adaptation is the process of becoming adapted to an environment. It is an anatomical (body parts), physiological (functions), or behavioral change that improves a population’s ability to survive.
  21. 21. “Survival of the Fittest” (nature selects)
  22. 22. Evolution by Artificial Selection• Artificial selection is the selective breeding of organisms, by humans, for specific desirable characteristics.• Dogs have been bred for certain characteristics.• Fruits, grains, and vegetables are also produced by artificial selection. Humans save seeds from the largest, and sweetest fruits. By selecting for these traits, farmers direct the evolution of crop plants to produce larger, sweeter crops.
  23. 23. Evolution by Resistance• Resistance is the ability of an organism to tolerate a chemical or disease-causing agent.• An organism may be resistant to a chemical when it contains a gene that allows it to break down a chemical into harmless substances.• Humans promote the evolution of resistant populations by trying to control pests and bacteria with chemicals.
  24. 24. Pesticide Resistance• A pesticide sprayed on corn to kill grasshoppers, for example, may kill most of the grasshoppers, but those that survive happen to have a gene that protects them from the pesticide. These surviving insects pass on this resistant gene to their offspring.• Each time the corn is sprayed, more resistant grasshoppers enter the population. Eventually the entire population will be resistant, making the pesticide useless.
  25. 25. Pesticide Resistance
  26. 26. Wrap Up (Mar. 1)Œ What is one fact that you learned today? What is the most interesting thing that you took away from the lesson?o How will you apply what you’ve learned to your life?

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