1. CAMPBELL BIOLOGY IN FOCUS © 2014 Pearson Education, Inc. Urry Cain Wasserman Minorsky Jackson Reece Lecture Presentations by Kathleen Fitzpatrick and Nicole Tunbridge 21 The Evolution of Populations

2. © 2014 Pearson Education, Inc. Overview: The Smallest Unit of Evolution  _________________________________________ _________________________________________ _________________________________________ ___

3. © 2014 Pearson Education, Inc. Figure 21.1

4. © 2014 Pearson Education, Inc. Figure 21.2 1978 (after drought) 10 1976 (similar to the prior 3 years) Average beak depth (mm) 9 8 0

5. © 2014 Pearson Education, Inc.  Microevolution _________________________________________ _________________________________________ __  3 mechanisms  __________________________________________  _________________________________________ _________________________________________ __

6. © 2014 Pearson Education, Inc. Figure 21.3

7. © 2014 Pearson Education, Inc.  __________________________________________ __________________________________________ Genetic Variation

8. © 2014 Pearson Education, Inc. Figure 21.5 (a) Caterpillars raised on a diet of oak flowers (b) Caterpillars raised on a diet of oak leaves

9. © 2014 Pearson Education, Inc. Altering Gene Number or Position  __________________________________________ __________________________________________  __________________________________________ __________________________________________ __________________________________________ __________________________________________

10. © 2014 Pearson Education, Inc. Concept 21.2: The Hardy-Weinberg equation can be used to test whether a population is evolving  population __________________________________________ __________________________________________  A gene pool __________________________________________ __________________________________________  __________________________________________ __________________________________________ __________________________________________

11. © 2014 Pearson Education, Inc. Figure 21.6 Porcupine herd Beaufort Sea Fortymile herd Porcupine herd range Fortymile herd range MAP AREA ALASKA CANADA NORTHWEST TERRITORIES YUKON ALASKA

12. © 2014 Pearson Education, Inc.  __________________________________________ __________________________________________ __________________________________________ The Hardy-Weinberg; Calculating Allele Frequencies

13. © 2014 Pearson Education, Inc. Conditions for Hardy-Weinberg Equilibrium  ___________________________________________ ___________________________________________ ___________________________________________  ___________________________________________ ___________________________________________

14. © 2014 Pearson Education, Inc.  ________________________________________ ________________________________________ 1.__________________________________ 2.__________________________________ 3.__________________________________ 4.__________________________________ 5.__________________________________

15. © 2014 Pearson Education, Inc.  __________________________________________ __________________________________________ __________________________________________

16. © 2014 Pearson Education, Inc.  p 2  2pq  q 2  1 _________________________________________ _________________________________________ _________________________________________ _________________________________________ ____ The Hardy-Weinberg equation

17. © 2014 Pearson Education, Inc.  ___________________________________________ Factors that change allele frequencies

18. © 2014 Pearson Education, Inc. Genetic Drift  Genetic drift __________________________________________ __________________________________________ __________________________________________ ___ Animation: Causes of Evolutionary Changes Animation: Mechanisms of Evolution

19. © 2014 Pearson Education, Inc. Figure 21.9-1 CWCWCWCW CRCRCRCR CRCWCRCW CRCRCRCR CRCRCRCR CRCRCRCR CRCRCRCR CRCWCRCW CRCWCRCW CRCWCRCW p (frequency of C R )  0.7 q (frequency of C W )  0.3 Generation 1

20. © 2014 Pearson Education, Inc. Figure 21.9-2 CWCWCWCW CRCRCRCR CRCWCRCW CRCRCRCR CRCRCRCR CRCRCRCR CRCRCRCR CRCWCRCW CRCWCRCW CRCWCRCW CWCWCWCW CRCRCRCR CRCWCRCW CRCRCRCR CRCRCRCR CRCWCRCW CRCWCRCW CRCWCRCW CWCWCWCW CWCWCWCW 5 plants leave offspring p (frequency of C R )  0.7 q (frequency of C W )  0.3 p  0.5 q  0.5 Generation 2Generation 1

21. © 2014 Pearson Education, Inc. Figure 21.9-3 CWCWCWCW CRCRCRCR CRCWCRCW CRCRCRCR CRCRCRCR CRCRCRCR CRCRCRCR CRCWCRCW CRCWCRCW CRCWCRCW CWCWCWCW CRCRCRCR CRCWCRCW CRCRCRCR CRCRCRCR CRCRCRCR CRCRCRCR CRCWCRCW CRCWCRCW CRCWCRCW CWCWCWCW CRCRCRCR CRCRCRCR CRCRCRCR CRCRCRCR CRCRCRCR CRCRCRCR CRCRCRCR CRCRCRCR CWCWCWCW 5 plants leave offspring 2 plants leave offspring p (frequency of C R )  0.7 q (frequency of C W )  0.3 p  0.5 q  0.5 p  1.0 q  0.0 Generation 2Generation 3Generation 1

22. © 2014 Pearson Education, Inc. The Founder Effect  founder effect - _________________________________________ _________________________________________ _________________________________________  _________________________________________ _________________________________________ _________________________________________

23. © 2014 Pearson Education, Inc. The Bottleneck Effect  __________________________________________ __________________________________________ __________________________________________ __________________________________________

24. © 2014 Pearson Education, Inc. Figure 21.10 Original population Surviving population Bottlenecking event (a) By chance, blue marbles are overrepresented in the surviving population. (b) Florida panther (Puma concolor coryi)

25. © 2014 Pearson Education, Inc. Figure 21.10a-1 Original population (a) By chance, blue marbles are overrepresented in the surviving population.

26. © 2014 Pearson Education, Inc. Figure 21.10a-2 Original population Bottlenecking event (a) By chance, blue marbles are overrepresented in the surviving population.

27. © 2014 Pearson Education, Inc. Figure 21.10a-3 Original population Surviving population Bottlenecking event (a) By chance, blue marbles are overrepresented in the surviving population.

28. © 2014 Pearson Education, Inc. Case Study: Impact of Genetic Drift on the Greater Prairie Chicken  _________________________________________ _________________________________________ _________________________________________ ___

29. © 2014 Pearson Education, Inc. Figure 21.11a Pre-bottleneck (Illinois, 1820) Post-bottleneck (Illinois, 1993) Range of greater prairie chicken Greater prairie chicken (a)

30. © 2014 Pearson Education, Inc. Figure 21.11b Illinois 1930–1960s 1993 Kansas, 1998 (no bottleneck) Nebraska, 1998 (no bottleneck) 1,000–25,000  50 75,000– 200,000 5.2 3.7 Location Population size 750,000 Number of alleles per locus Percentage of eggs hatched 93  50 5.8 99 96 (b)

31. © 2014 Pearson Education, Inc.  _________________________________________ _________________________________________ _________________________________________ ___  _________________________________________ _________________________________________ _________________________________________ _________________________________________ ____

32. © 2014 Pearson Education, Inc. Gene Flow  Gene flow - __________________________________________ __________________________________________  __________________________________________ __________________________________________ __________________________________________

33. © 2014 Pearson Education, Inc.  __________________________________________ __________________________________________ __________________________________________ __________________________________________ Concept 21.4: Natural selection is the only mechanism that consistently causes adaptive evolution

34. © 2014 Pearson Education, Inc. Directional, Disruptive, and Stabilizing Selection  3 modes of natural selection  _________________________________________ _________________________________________  _________________________________________ _________________________________________ _________________________________________

35. © 2014 Pearson Education, Inc. Figure 21.13 Original population Evolved population Original population Frequency of individuals Phenotypes (fur color) (a) Directional selection (b) Disruptive selection(c) Stabilizing selection

36. © 2014 Pearson Education, Inc. Figure 21.14 Bones shown in green are movable. Ligament

37. © 2014 Pearson Education, Inc. Figure 21.14a

38. © 2014 Pearson Education, Inc. Sexual Selection  __________________________________________ ________________________________________

39. © 2014 Pearson Education, Inc. Figure 21.15

40. © 2014 Pearson Education, Inc. The Preservation of Genetic Variation  _________________________________________ _________________________________________

41. © 2014 Pearson Education, Inc. Balancing Selection  _________________________________________ _________________________________________ ___________________________________________  _________________________________________

42. © 2014 Pearson Education, Inc.  __________________________________________ __________________________________________ __________________________________________  ______________________________________

43. © 2014 Pearson Education, Inc. Figure 21.17 Distribution of malaria caused by Plasmodium falciparum (a parasitic unicellular eukaryote) Key Frequencies of the sickle-cell allele 10.0–12.5%  12.5% 7.5–10.0% 5.0–7.5% 2.5–5.0% 0–2.5%

44. © 2014 Pearson Education, Inc.  _________________________________________ _________________________________________ ___________________________________________ _______________________________________  example, frequency-dependent selection selects for equal numbers of “right-mouthed” and “left-mouthed” scale-eating fish

45. © 2014 Pearson Education, Inc. Figure 21.18 “Left-mouthed” P. microlepis “Right-mouthed” P. microlepis Sample year Frequency of “left-mouthed” individuals 1981 ’83 ’85’87’89 0.5 0 1.0

46. © 2014 Pearson Education, Inc. Figure 21.19