Unit 17b Domains and kingdoms

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Unit 17b Domains and kingdoms

  1. 1. KEY CONCEPT Molecular clocks provide clues to evolutionary history.<br />
  2. 2. Mutations add up at a fairly<br />constant rate in the DNA of species that evolved from a common ancestor.<br />Ten million years later—<br />one mutation in each lineage<br />Another ten million years later—<br />one more mutation in each lineage<br />Molecular clocks use mutations to estimate evolutionary time.<br />Mutations add up at a constant rate in related species.<br />This rate is the ticking of the molecular clock.<br />As more time passes, there will be more mutations.<br />The DNA sequences from two<br />descendant species show mutations<br />that have accumulated (black).<br />The mutation rate of this<br />sequence equals one mutation<br />per ten million years.<br />DNA sequence from a<br />hypothetical ancestor<br />
  3. 3. Scientists estimate mutation rates by linking molecular data and real time.<br /><ul><li>an event known to separate species
  4. 4. the first appearance of a species in fossil record</li></li></ul><li>Mitochondrial DNA and ribosomal RNA provide two types of molecular clocks.<br /><ul><li>Different molecules have different mutation rates.
  5. 5. higher rate, better for studying closely related species
  6. 6. lower rate, better for studying distantly related species</li></li></ul><li>grandparents<br />mitochondrial<br />DNA<br />nuclear DNA<br />parents<br />Mitochondrial DNA is<br />passed down only from <br />the mother of each generation,so it is not subject to recombination.<br />child<br />Nuclear DNA is inherited from both<br />parents, making it more difficult to<br />trace back through generations.<br /><ul><li>Mitochondrial DNA is used to study closely related species.
  7. 7. mutation rate ten times faster than nuclear DNA
  8. 8. passed down unshuffled from mother to offspring</li></li></ul><li><ul><li>Ribosomal RNA is used to study distantly related species. What would you expect the mutation rate to be – high or low?
  9. 9. many conservative regions
  10. 10. lower mutation rate than most DNA</li></li></ul><li>KEY CONCEPT The current tree of life has three domains.<br />
  11. 11. Plantae<br />Animalia<br />Classification is always a work in progress. Why? <br />The tree of life shows our most current understanding. <br />New discoveries can lead to changes in classification.<br />Until 1866: only two kingdoms,Animalia and Plantae<br />
  12. 12. Protista<br />Classification is always a work in progress. <br />The tree of life shows our most current understanding. <br />New discoveries can lead to changes in classification.<br />Until 1866: only two kingdoms,Animalia and Plantae<br />Plantae<br />Animalia<br /><ul><li>1866: all single-celled organisms moved to kingdom Protista </li></li></ul><li>Plantae<br />Animalia<br />Protista<br />Monera<br />Classification is always a work in progress. <br />The tree of life shows our most current understanding. <br />New discoveries can lead to changes in classification.<br />Until 1866: only two kingdoms,Animalia and Plantae<br /><ul><li>1866: all single-celled organisms moved to kingdom Protista
  13. 13. 1938: prokaryotes moved to kingdom Monera</li></li></ul><li>Plantae<br />Animalia<br />Protista<br />Fungi<br />Classification is always a work in progress. <br />The tree of life shows our most current understanding. <br />New discoveries can lead to changes in classification.<br />Until 1866: only two kingdoms,Animalia and Plantae<br /><ul><li>1866: all single-celled organisms moved to kingdom Protista
  14. 14. 1938: prokaryotes moved to kingdom Monera
  15. 15. 1959: fungi moved to own kingdom</li></ul>Monera<br />
  16. 16. Plantae<br />Animalia<br />Protista<br />Archea<br />Bacteria<br />Fungi<br />Classification is always a work in progress. <br />The tree of life shows our most current understanding. <br />New discoveries can lead to changes in classification.<br />Until 1866: only two kingdoms,Animalia and Plantae<br /><ul><li>1866: all single-celled organisms moved to kingdom Protista
  17. 17. 1938: prokaryotes moved to kingdom Monera
  18. 18. 1959: fungi moved to own kingdom
  19. 19. 1977: kingdom Monerasplit into kingdoms Bacteria and Archaea </li></li></ul><li>The three domains in the tree of life are Bacteria, Archaea, and Eukarya.<br />Domains are above the kingdom level. <br />proposed by Carl Woese based on rRNA studies of prokaryotes<br />domain model more clearly shows prokaryotic diversity <br />
  20. 20. <ul><li>Domain Bacteria includes prokaryotes in the kingdom Bacteria.
  21. 21. one of largest groups on Earth
  22. 22. classified by shape, need for oxygen, and diseases caused</li></li></ul><li><ul><li>Domain Archaea includes prokaryotes in the kingdom Archaea.
  23. 23. cell walls chemically different from bacteria
  24. 24. differences discovered by studying RNA
  25. 25. known for living in extreme environments. What advantage(s) is there to living in an extreme environment?</li></li></ul><li><ul><li>Domain Eukarya includes all eukaryotes.
  26. 26. kingdom Protista</li></li></ul><li><ul><li>Domain Eukarya includes all eukaryotes.
  27. 27. kingdom Protista
  28. 28. kingdom Plantae</li></li></ul><li><ul><li>Domain Eukarya includes all eukaryotes.
  29. 29. kingdom Protista
  30. 30. kingdom Plantae
  31. 31. kingdom Fungi</li></li></ul><li><ul><li>Domain Eukarya includes all eukaryotes.
  32. 32. kingdom Protista
  33. 33. kingdom Plantae
  34. 34. kingdom Fungi
  35. 35. kingdom Animalia</li></li></ul><li>bridge to transfer DNA<br /><ul><li>Bacteria and archaea can be difficult to classify.
  36. 36. transfer genes among themselves outside of reproduction
  37. 37. blurs the linebetween “species”
  38. 38. more researchneeded tounderstand prokaryotes</li></li></ul><li>Which of the following is not a feature of a cladogram? <br />A. nodes <br />B. derived characters <br />C.clades<br />D.taxons<br />
  39. 39. Which of the following is not a feature of a cladogram? <br />A. nodes <br />B. derived characters <br />C.clades<br />D.taxons<br />Correct Answer = D<br />What is true about two organisms that share the same common ancestor? <br />A. They have no common derived characters. <br />B. They are in the same clade. <br />C. They are not closely related. <br />D. They evolved at the same time. <br />
  40. 40. Which of the following is not a feature of a cladogram? <br />A. nodes <br />B. derived characters <br />C.clades<br />D.taxons<br />Correct Answer = D<br />What is true about two organisms that share the same common ancestor? <br />A. They have no common derived characters. <br />B. They are in the same clade. <br />C. They are not closely related. <br />D. They evolved at the same time. <br />Correct Answer = B<br />
  41. 41. Review<br />DNA mutations give clues to evolutionary time and relationships<br />Nuclear DNA, mitochondrial DNA and ribosomal RNA mutate at different rates<br />As scientific discoveries were made, the number of kingdoms changed and domains were added<br />

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