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PKA: Answer on your own paper and turn in to Ms. Deel

PKA: Answer on your own paper and turn in to Ms. Deel. 1. Do populations of organisms change over time? How do you know? 2. Why would organisms need to change? 3. Is there evidence that any organisms living today have experienced any change?

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PKA: Answer on your own paper and turn in to Ms. Deel

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  1. PKA: Answer on your own paper and turn in to Ms. Deel • 1. Do populations of organisms change over time? How do you know? • 2. Why would organisms need to change? • 3. Is there evidence that any organisms living today have experienced any change? • 4. What factors would contribute to any change?

  2. What did this organism look like when it was alive? http://www.sciencemag.org/site/multimedia/slideshows/343.6169.dino/dino.slideshow.html

  3. Horse Evolution Lab www.docstoc.com

  4. www.itsokaytobesmart.com

  5. What changes occurred and why? www.fillthevoid.org

  6. http://www.sepa.duq.edu/darwin/education-tools-horseFeet.shtmlhttp://www.sepa.duq.edu/darwin/education-tools-horseFeet.shtml

  7. Fossils • Fossils: Any trace or remains of an organism that has been preserved by a natural process • Comparing structure of fossils with present day organisms allows us to infer evolutionary relationships www.mindbodyspiritonline.co.uk

  8. Evolution: Change over time • Geological Evolution: the evolution of the Earth itself • Organic Evolution: the evolution of living things

  9. Most of the time organisms decay without leaving a trace causing the fossil record to be incomplete • Why would organisms that die not be fossilized? • Not in sedimentary rock • Decay quickly • Get eaten • Ex- tropical rain forest organisms decay too fast

  10. Fossils are found in Sedimentary rock www.en.uni-muenchen.de Sedimentary rocks are formed by sediment that is deposited over time, usually as layers at the bottom of lakes and oceans.

  11. Types of Fossils • 1.    Amber and Ice • 2.    Bones and Petrification • 3.    Molds, Casts, and Imprints

  12. Age of fossils • 1.    Relative dating • Age determined by relating fossil to others • Use index fossils- fossils found only during on period of time • Law of Superposition: Layers on the top were deposited later than layers on the bottom; layers on the bottom are older than on the top

  13. Law of Superposition tle.westone.wa.gov.au

  14. Which layer is the youngest? Oldest? ufo-connguoi-thuongde.blogspot.com

  15. http://quizlet.com/4079105/relativeabsolute-age-datingfossils-flash-cards/http://quizlet.com/4079105/relativeabsolute-age-datingfossils-flash-cards/

  16. 2.    Absolute Dating • Radioactive dating gives more precise time • Radioactive Dating: use rate of decay of radioactive elements found in organisms to find their absolute age. • Ex: carbon dating

  17. The universe is full of naturally occurring radioactive elements. Radioactive atoms are unstable • Over time, radioactive “parent atoms” decay into stable “daughter atoms.” • Half life: how many years it takes for half of the amount of an element to decay.

  18. Radioactive Decay Example • Carbon-14 has a half life of 5,730 years. If the original amount of C-14 in a dead horse is 14g, how old is the organism if the amount of C-14 is currently 7g? If 3.5g is left? • 5,730 years • 11,460 years

  19. Evolution is the change in the inherited characteristics of populations over successive generations • Darwin vs. Lamarck ciencialibrecolombia.wordpress.com

  20. Lamarck • 1. Tendency towards perfection- all organisms have the urge to become better. • 2. Use and Disuse- organisms can alter their traits by use or disuse • 3. Acquired characteristics- the traits that an organism acquires during a lifetime will be passed on to offspring

  21. Darwin • 1. Overproduction- Each species produces more offspring than can survive to adulthood • 2. Competition/Struggle- Because of overproduction, organisms must compete for resources like water, shelter, food, escape predators • 3. Genetic Variation- variations or differences occur among members of the same species

  22. Darwin • 4. Survival of the fittest/ Natural Selection- Organisms with traits that make them well adapted to their environment have a better chance of surviving to adulthood to reproduce and therefore passing on their well adapted genes to the next generation • 5. As natural selection continues over generations, species change and become better adapted to their environment= EVOLUTION

  23. Whose theory was correct?

  24. Example: Giraffes • Using the theories to explain why giraffes have such long necks

  25. Example: Giraffes • Lamarck: 1. Giraffes want longer necks 2. They stretched their necks a lot to reach leaves high on trees 3. They passed the long neck trait they acquired on to their offspring

  26. Example: Giraffes • Darwin: 1. Over production- too many giraffes 2. Struggle- not enough food, leaves high on trees 3. Variation- Giraffes with short, medium, and long necks

  27. Example: Giraffes • Darwin Continued: 4. Natural Selection- the giraffes with the long necks could reach the higher leaves and survive to reproduce more than others 5. After generations the giraffes with short and medium necks died out and long necked giraffes increased in the population.

  28. Example: Darwin’s Finches • Using the theories to explain who finches where there are large, hard seeds to eat have evolved large thick beaks.

  29. Example: Darwin’s Finches • Lamark: 1. Finches want bigger beaks. 2. Finches use their beaks a lot and they got thick 3. They passed the thick beak trait they acquired on to their offspring

  30. Example: Darwin’s Finches • Darwin: 1. Over production- too many finches 2. Competition- not enough food, only large seeds 3. Variation- Finches with small, medium, and large beaks

  31. Example: Darwin’s Finches • Darwin Continued: 4. Natural Selection- the finches with the large thick beaks could open seeds and survive to reproduce more than others 5. After generations the finches with short and medium beaks died out and large beaked finches increased in the population.

  32. Evidence of Evolution, Evolution of Populations

  33. Evolution- a change in a population over time • Gene pool- all genes in a population • Population- groups of interbreeding individuals that live in the same place at the same time

  34. How are these structures alike?How are they different?

  35. Evidence that organisms descended from a common ancestor • 1. Homologous body structures: Structures that have different mature forms but develop from the same embryonic tissue. • Ex- The forelimbs of vertebrates

  36. www.bio.miami.edu

  37. 2. Vestigial structures: Structures that no longer function or function less than in an ancestor, but are present because they are left over from an ancestor. • Ex- Tailbone in humans, appendix in humans, wisdom teeth in humans, toe on a boa

  38. 3. Similarities in Embryology: The more similarly the embryos of different organisms develop the more closely related they are.

  39. 4. Darwin’s Finches: there are 13 species of finches on the Galapagos that descended from 1 common ancestor from the mainland of South America. Similar because inherited similar DNA from common ancestor, different because environmental pressures caused natural selection.

  40. 5. Antibiotic Resistance in Bacteria: • Back to Darwin’s idea’s • Overpopulation- too many bacteria • Struggle- antibiotics • Variation- some bacteria have genetic resistance to antibiotics, some do not

  41. Survival of the fittest- the bacteria that are resistant survive and reproduce more • Evolution-there is an increase in antibiotic resistant bacteria

  42. 6. Pesticide resistance in Tobacco Budworm • Over time the Tobacco Budworm has become resistant to pesticides. Using Darwin’s Theory to explain this phenomenon • 1968-tobacco budworm infestation; farmers sprayed pesticide and killed budworms • 1969-small infestation; farmers sprayed; pesticide didn’t help • 1970- infestation; farmers sprayed; pesticide didn’t work

  43. 7. Sickle Cell Anemia & Malaria: • Sickle Cell Anemia is a deadly genetic disease; causes blood cells to form a sickle shape; gene common in tropical Africa and Asia • Malaria- leading cause of death in Africa; a pathogenic disease caused by a protist that is transmitted by the bite of a certain mosquito found in tropics

  44. Why has natural selection not eliminated the harmful gene? • AA- does not have sickle cell, NOT resistant to malaria • Aa- does not have sickle cell, resistant to malaria • Aa- has sickle cell anemia, resistant to malaria

  45. Individuals heterozygous have a better chance of surviving and reproducing

  46. www.mhhe.com

  47. Toothpick Fish Lab Weedy Sea Dragon www.ripleyaquariums.com

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