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Examples of Evolution by Natural Selection

Examples of Evolution by Natural Selection. Microevolution vs. Macroevolution Microevolution is intraspecific evolution, evolution WITHIN a species. Macroevolution is speciation. One species evolves into a new species. Examples of Evolution by Natural Selection.

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Examples of Evolution by Natural Selection

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  1. Examples of Evolution by Natural Selection Microevolution vs. Macroevolution • Microevolution is intraspecific evolution, evolution WITHIN a species. • Macroevolution is speciation. One species evolves into a new species.

  2. Examples of Evolution by Natural Selection Example #1: Antibiotic Resistance This is a famous example, known by almost everyone but rarely called “evolution.” But it is !!! We hear “resistance develops” or resistance emerges” etc. In fact, resistance evolves.* AR is a fine example of very fast evolution AND A fine example of one way Darwinian evolution is important to your health and well-being. *They DO NOT “become immune to the antibiotics.” This phenomenon is NOTHING like you getting a flu shot!!

  3. Examples of Evolution by Natural Selection Example #1: Antibiotic Resistance AR is the “poster-child” for rapid evolution.* If we develop a new antibiotic this year and… a resistant strain of bacteria develops in a London hospital … resistant strains will evolve and be in all London hospitals in 6 months and… they will be observed in Hong Kong in two years, i.e. they will have moved around the Earth in two years. How does that happen? *Steven Sterns, Yale U.

  4. Examples of Evolution by Natural Selection Example #1: Antibiotic Resistance

  5. Examples of Evolution by Natural Selection Example #2: Pesticide Resistance • Insecticides, Fungicides, Herbicides (see first page of chapter 13) Consider DDT, the first widely used synthetic insecticide.

  6. Examples of Evolution by Natural Selection Example #2: Pesticide Resistance • Insecticides, Fungicides, Herbicides Consider DDT, the first widely used synthetic insecticide. • Species Resistant to Insecticides • 1948:14 • 1956:69 • 1970: 224 • 1976: 364 • 1984: 447 • 1989: 504

  7. Example #2: Pesticide ResistanceHerbicide Resistance in 6 Species of Plants in Czech Republic

  8. Examples of Evolution by Natural Selection Example #3: The Peppered Moth Biston betularia Industrial Melanism in a Night-flying Moth

  9. The Peppered Moth, Bistonbetulariaan example of directional selection Fig. 18-6a1, p.288

  10. Natural Selection in the Peppered Moth

  11. H.B.D. Kettlewell Mark and Recapture Experiments (using caged females w/ pheromones) %Recaptured Woodland    Melanics    Pepper Urban            27.5%         13.0% Rural               6.3%          12.5% This shows a difference but does not prove that birds CAUSED it. Differential Predation Observations (freshly killed moths placed on trees and watched) # moths eaten by birds Woodland            Melanics        Pepper Urban                    15                  43 Rural                     164                 26 Science is “roll up your sleeves” process… HBD doesn’t even wear a shirt !!! ;-) Industrial melanism is seen in more than 70 species of British moths; all show patterns similar to that seen in B. betularia.

  12. Evolution by Natural Selection: The Peppered Moth Left: Kettelwell, 1956 Right: Grant et.al. 1998 Grant's comments on these maps: "The maps show a before-after comparison of the geographic distribution of melanic phenotypes in peppered moth populations in Britain based on Kettlewell's 1956 survey (left map) and that conducted 40-years later (1996) by my colleagues and me (right map). The black segments of the pie charts indicate the percentage of melanics at the various locations. Clearly melanism has declined everywhere it was once common." (Grant, personal communication, February 11, 2002) The source publication for these maps: Grant, B. S., Cook, A. D. , Clarke, C. A., and Owen, D. F. 1998. Geographic and temporal variation in the incidence of melanism in peppered moth populations in America and Britain. Journal of Heredity 89:465-471.

  13. Examples of Evolution by Natural Selection Example #4: Sickle-cell Anemia and Malaria

  14. Example #4: Sickle-cell Anemia and Malaria Okay, let’s simplify it… HbA = “N” = normal HbS = “S” = sickle cell NN = “normal” Ns = “normal but carrier” sN = “normal but carrier” ss = sickle-cell anemia

  15. The Genetic Basis of Sickle Cell AnemiaHbAvsHbβ: Everyone has HbA (141), and Hb-non-A (146)”HbS is a mutant form of HbA

  16. The Genetic Basis of Sickle Cell Anemia

  17. less than 1 in 1,600 1 in 400-1,600 1 in 180-400 1 in 100-180 1 in 64-100 more than 1 in 64 The Distribution of the Sickle-Cell Gene Fig. 18-13b, p.293

  18. Malaria: the Plasmodium parasiteSickle cell anemia is a genetic disease of the blood.Malaria is parasitic disease of the blood. What is the relationship between these two diseases?

  19. The Distribution of Falciparum Malaria Fig. 18-13a, p.293

  20. Geographic Distribution of Malaria vs. Sickle-cell Anemia

  21. Sickle-Cell Trait: Heterozygote Advantageor heterosis or hybrid vigor • Allele HbS causes sickle-cell anemia when homozygous • Heterozygotes (NS) • are more resistant to malaria than homozygotes (SS or NN) Malaria case Sickle-cell trait less than 1 in 1,600 1 in 400-1,600 1 in 180-400 1 in 100-180 1 in 64-100 more than 1 in 64

  22. What Is Our View of Darwin’s Idea Today?The Modern Synthesis: Darwinism Meets Genetics • To his credit, his idea has withstood the scrutiny of about 150 years of scientific testing. • But a lot has happened in 150 years.

  23. What Is Our View of Darwin’s Idea Today? Neo-Darwinism = The Modern Synthesis Neo-Darwinism @ Darwin + Modern Genetics

  24. Neo-Darwinism @ Darwin + Modern Genetics What Is Our View of Darwin’s Idea Today? Neo-Darwinism = The Modern Synthesis

  25. Neo-Darwinism @ Darwin + Modern Genetics What Is Our View of Darwin’s Idea Today? Neo-Darwinism = The Modern Synthesis

  26. Neo-Darwinism @ Darwin + Modern Genetics What Is Our View of Darwin’s Idea Today? Neo-Darwinism = The Modern Synthesis

  27. Neo-Darwinism @ Darwin + Modern Genetics What Is Our View of Darwin’s Idea Today? Neo-Darwinism = The Modern Synthesis

  28. What Is Our View of Darwin’s Idea Today? Neo-Darwinism = The Modern SynthesisNeo-Darwinism @ Darwin + Modern Genetics And also every other branch of biology that has grown since 1859 and contributes to our understanding of Darwin’s idea, i.e. all of them. Especially... • All the “Comparatives” • Comparative Anatomy (morphology) • Comparative Embryology (development) • Comparative Ethology (behavior) • Comparative Biochemistry (molecular biology: proteins and DNA) • Biogeography (where do they live and why?) • Paleontology (the fossil record) • Vestigial Structures (the “scars” of evolution)

  29. Neo-Darwinism = The Modern Synthesisevidence from Comparative Anatomy (morphology)

  30. Comparative Anatomyhomologous structures (vs analogous structures) Bat Human Whale Cat Figure 13.8

  31. Comparative Anatomyhomologous structures (vs analogous structures) Bat Human Whale Cat Figure 13.8

  32. Comparative Embryology

  33. Neo-Darwinism = The Modern Synthesisevidence fromComparative Embryology (development)

  34. Comparative Embryology Pharyngeal pouches Post-anal tail Chicken embryo Human embryo Figure 13.9

  35. Neo-Darwinism = The Modern Synthesis evidence from Molecular Biology(Comparative Biochemistry)

  36. Neo-Darwinism = The Modern Synthesis evidence from Comparative Biochemistry(= comparative molecular biology) What mutation could cause isoleucine (Ile) to change to phenylalanine (Phe)? And what mutation can change Leucine (Leu) to Arginine (Arg)

  37. Percent of selected DNA sequences that match a chimpanzee’s DNA Primate 100% 92% 96% Chimpanzee Human Gorilla Orangutan Gibbon Old World monkey Figure 13.10

  38. Neo-Darwinism = The Modern Synthesis evidence from Comparative BiochemistryWe can calculate rates of mutation particularly in very stable genes or pseudogenes and use them as clocks Cytochrome C: yeast, wheat, human

  39. Neo-Darwinism = The Modern Synthesis evidence from Biogeography

  40. Present Cenozoic Eurasia North America 65 Africa India South America Madagascar Australia Antarctica Laurasia 135 Gondwana Mesozoic 251 million years ago Pangaea Paleozoic Figure 14.17

  41. Neo-Darwinism = The Modern Synthesisevidence from Paleontology (fossils)

  42. Neo-Darwinism = The Modern Synthesisevidence from Paleontology: The Fossil Record

  43. Fossil Record

  44. Neo-Darwinism = The Modern Synthesisevidence from Vestigial Structures

  45. The Recurrent Laryngeal Nervevestiges, the “scars” of evolution

  46. The Recurrent Laryngeal Nervevestiges, the “scars” of evolution

  47. Neo-Darwinism = The Modern Synthesisevidence from Vestigial Structures

  48. Neo-Darwinism = The Modern Synthesisevidence from Vestigial Structures

  49. Does Evolution occur by mechanisms other than natural selection? • YES. Evolution can… • be slow or fast; • and it can be helpful, harmful or neutral.

  50. Does Evolution occur by mechanisms other than natural selection? OK, how about this question… Does Evolution not occur?

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