1. Module 1: Evolution MonthDayTopic Sept8Mechanisms of evolution I 11Mechanisms of evolution II 13Speciation 15Macroevolution 18Biodiversity 20The history of plants 22Molecular evolution 25 27 Exam review First mid-term exam

2. Microevolution Change in the frequencies of genotypes in a population The formation of new species Macroevolution

3. Species ASpecies B Time

4. Species A Species B Species A Species B Species C Time

5. A species is... a group of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

6. A species is... a group of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

7. A species is... a group of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

8. A species is... a group of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

9. But what about asexual organisms?

10. How do new species form? When gene flow ends between natural populations and their gene pool changes

11. Once a barrier to gene flow is established... populations diverge because of microevolution

12. How do new species form? 1.Allopatric speciation 2.Sympatric speciation 3.Parapatric speciation

13. 1. Allopatric speciation Literally “other country”

14. 1. Allopatric speciation Literally “other country” Geographic barrier divides population or Part of population crosses barrier and “founds” new population

15. 1. Allopatric speciation Literally “other country” Geographic barrier divides population or Part of population crosses barrier and “founds” new population Most prevalent form of speciation

16. Allopatric speciation Geographic barrier divides population Gene flow is cut off Microevolution takes over Populations differentiate

17. Fig. 19-1, p.300

18. Fig. 19-7d13, p.305 Housefinch (Carpodacus)

21. Fig. 19-7d12, p.305 Iiwi (Vestiaria coccinea)

23. 2. Sympatric speciation Literally “same country”

24. 2. Sympatric speciation Literally “same country” Species arise from a connected population

25. 2. Sympatric speciation Literally “same country” Species arise from a connected population Most common in plants

26. 2. Sympatric speciation Literally “same country” Species arise from a connected population Most common in plants Occasionally seen in animals

27. Speciation by polyploidy (plants) Mistake during cell division

28. Speciation by polyploidy (plants) Mistake during cell division New individual is viable but genetically isolated

29. Speciation by polyploidy (plants) Mistake during cell division New individual is viable but genetically isolated In plants, individual with new ploidy- level can often self-fertilize

30. Triticum monococcum (einkorn) T. aestivum (one of the common bread wheats) Unknown species of wild wheat T. turgidum (wild emmer) T. tauschii (a wild relative) 42AABBDD14AA14BB14AB28AABB14DDXX cross-fertilization, followed by a spontaneous chromosome doubling Speciation by polyploidy

31. Speciation by behavioral change (animals) Parents make “mistake”

32. Speciation by behavioral change (animals) Parents make “mistake” Young pattern on a new place

33. Speciation by behavioral change (animals) Parents make “mistake” Young pattern on a new place Young return to place to mate

34. Speciation by behavioral change (animals) Parents make “mistake” Young pattern on a new place Young return to place to mate No gene flow with original population

36. 3. Parapatric speciation Like allopatric speciation, except boundary is not physical

37. 3. Parapatric speciation Like allopatric speciation, except boundary is not physical Parts of a population experience different conditions

38. 3. Parapatric speciation Like allopatric speciation, except boundary is not physical Parts of a population experience different conditions Natural selection is stronger than gene flow

39. Bullock’s orioleBaltimore oriole hybrid zone Parapatric speciation

40. Can species interbreed if they get back together?

41. Species of European and American sycamores have been separated for 20 million years, yet they can still interbreed

42. Reproductive barriers between species Prezygotic barriers –barriers that prevent mating

43. Reproductive barriers between species Prezygotic barriers –barriers that prevent mating Postzygotic barriers –Barriers that operate after mating occurs

44. Prezygotic barriers Behaviorial isolation Ecological isolation Temporal isolation Mechanical isolation Gametic isolation

45. Fig. 19-4c, p.302

46. Fig. 19-4d, p.302

47. Fig. 19-4e, p.302

48. Fig. 19-4b, p.302

49. Fig. 19-4a, p.302

50. Fig. 18-20, p.299

51. Postzygotic barriers Hybrid abnormality Hybrid infertility Low hybrid viability Absence or sterility of one sex

53. Fig. 19-21, p.317

55. What controls the rate at which new species form?

56. Species richness

57. What controls the rate at which new species form? Species richness Range size and mobility

58. What controls the rate at which new species form? Species richness Range size and mobility Behavior, especially mate choice

59. What controls the rate at which new species form? Species richness Range size and mobility Behavior, especially mate choice Environmental change

60. What controls the rate at which new species form? Species richness Range size and mobility Behavior Environmental change Life history

61. What controls the rate at which new species form? Species richness Range size and mobility Behavior Environmental change Life history “Empty space”

62. Hawaiian silverswords

63. 4 th mass extinction 210 mya: ~65% of species 5 th mass extinction 65 mya: ~76% of species Extraterrestrial impact or volcanism?

64. What controls the rate at which new species form? Species richness Range size Behavior Environmental change Generation time “Empty space” Innovation

66. Proportional Changes in Skull Chimpanzee Human Figure 19.14b Page 315