1. Chapter 24 The Origin of Species

2. Question? u What is a species? u Comment - Evolution theory must also explain how species originate.

3. Two Concepts of Species

4. Morphospecies

5. Problem u Where does extensive phenotype variation fit?

6. Two Schools

7. Biological Species

8. Key Points Heaven Scent an F1 hybrid between 2 species, but sterile.

9. Morphospecies & Biological Species

10. Speciation Requires:

11. Reproductive Barriers

12. Main Types of Barriers

13. Prezygotic - Types

14. Habitat Isolation

15. Behavioral Isolation

16. Temporal Isolation

17. Mechanical Isolation

18. Gametic Isolation

19. Postzygotic Types

20. Reduced Hybrid Viability

21. Reduced Hybrid Fertility

22. Hybrid Breakdown

23. Other Concepts of Species

24. Recognition Species Concept

25. Cohesion Species Concept

26. Ecological Species Concept

27. Evolutionary Species Concept

28. Comment u AP exam will focus on morphological and biological species concepts.

29. Modes of Speciation

31. Allopatric Speciation

32. Example

33. Another Example

34. Conditions Favoring Allopatric Speciation

36. Result

37. Comment

38. Examples

39. Adaptive Radiation

40. Mechanism

41. When the Environment Saturates

42. Sympatric Speciation

44. Plants

45. Polyploid Types

46. Autopolyploid

47. Allopolyploid

48. Animals

49. Gradualism Evolution

50. Gradualism Predicts:

51. Problem

52. Punctuated Evolution

53. Punctuated Equilibrium

54. Predictions

57. Possible Mechanism

58. Comment

59. Origin of Evolutionary Novelty

60. Exaptation

61. Heterochrony

62. Allometric Growth

64. Paedomorphosis

66. Ex - Homeosis

68. Gene Duplications

69. Future of Evolution ? u Look for new theories and ideas to be developed, especially from new fossil finds and from molecular (DNA) evidence.

70. Evolutionary Trends u Evolution is not goal oriented. It does not produce “perfect” species. u Remember – species survive because of their adaptations. They don’t adapt to survive.

72. Summary u Be able to discuss the main theories of what is a “species”. u Know various reproductive barriers and examples.

73. Summary u Know allopatric and sympatric speciation. u Be able to discuss gradualism and punctuated equilibrium theories.

74. Summary u Recognize various ideas about the origin of evolutionary novelties.