1. Pollinator-mediated Speciation in Angiosperms: What Do We Know?

2. Lecture Overview Vascular plant diversity Modes of angiosperm speciation Pollination modes and angiosperm diversification Experiments: pollinator-mediated selection on floral traits Conclusions

3. Lecture Overview Vascular plant diversity Modes of angiosperm speciation Pollination modes and angiosperm diversification Experiments: pollinator-mediated selection on floral traits Conclusions

4. Vascular Plant Diversity 260,000+ species

5. Vascular Plant Diversity 260,000+ species ~ 850 gymnosperms (290 mya) ~ 9800 ferns and fern allies (400 mya) ~ 249,000 angiosperms (130 mya)

7. Rapid diversification of angiosperms: “Abominable mystery”

8. His attempt to identify a single cause: “wretchedly poor”

9. Lecture Overview Vascular plant diversity Modes of angiosperm speciation Pollination modes and angiosperm diversification Experiments: pollinator-mediated selection on floral traits Conclusions

10. Modes of Angiosperm Speciation (speciation = reproductive isolation)

11. Mechanical barriers (e.g., mountain range)

13. Modes of Angiosperm Speciation (speciation = reproductive isolation) Mechanical barriers (e.g., mountain range) Genomic events - polyploidy (e.g., diploid to tetraploid)

15. Modes of Angiosperm Speciation (speciation = reproductive isolation) Mechanical barriers (e.g., mountain range) Genomic events - polyploidy (e.g., diploid to tetraploid) - chromosomal rearrangements

16. Modes of Angiosperm Speciation (speciation = reproductive isolation) Mechanical barriers (e.g., mountain range) Genomic events - polyploidy (e.g., diploid to tetraploid) - chromosomal rearrangements - Pollinator-mediated reproductive isolation - evolution of different floral morphologies

21. Lecture Overview Vascular plant diversity Modes of angiosperm speciation Pollination modes and angiosperm diversification Experiments: pollinator-mediated selection on floral traits Conclusions

22. Pollination Mode and Diversification Pollination = transfer of pollen to stigma

23. Anther Stigma Petal Sepal

24. Anther Stigma Petal Sepal

25. Anther Stigma Petal Sepal

26. Pollination Mode and Diversification Pollination = transfer of pollen to stigma - > 99% of gymnosperm species wind-pollinated

27. Pollination Mode and Diversification Pollination = transfer of pollen to stigma - > 99% of gymnosperm species wind-pollinated - > 80% of angiosperms are animal-pollinated

28. Pollinators and angiosperm speciation: correlations Angiosperm and insect diversification co- occurred

29. Pollinators and angiosperm speciation: correlations Angiosperm and insect diversification co- occurred Animal-pollination correlated with species richness at family level

30. Correlation ≠ Causation

31. Blood Pressure Income

36. Lecture Overview Vascular plant diversity Modes of angiosperm speciation Pollination modes and angiosperm diversification Experiments: pollinator-mediated selection on floral traits Conclusions

37. Two Important Studies Polemonium viscosum (alpine skypilot) and bumblebees (Galen, 1996)

39. Timberline 11,000 ft. Corolla tube width = 16 mm

40. Timberline 11,000 ft. Alpine - 12,000 ft. Corolla tube width = 18 mm Corolla tube width = 16 mm

41. Timberline 11,000 ft. Alpine - 12,000 ft. Corolla tube width = 18 mm Corolla tube width = 16 mm = 11% difference in corolla tube width

42. Timberline 11,000 ft. Alpine - 12,000 ft. Corolla tube width = 18 mm Corolla tube width = 16 mm What explains corolla tube width difference? = 11% difference in corolla tube width

43. Timberline 11,000 ft. Alpine - 12,000 ft. Corolla tube width = 18 mm Corolla tube width = 16 mm What explains corolla tube width difference? Solitary bees

44. Timberline 11,000 ft. Alpine - 12,000 ft. Corolla tube width = 18 mm Corolla tube width = 16 mm What explains corolla tube width difference? Solitary bees Bumble bees

45. Conclusions Bumblebees selected for wide corolla Evolution from 16mm to 18 mm corolla ~20 yrs Pollinator preference can cause floral trait evolution

46. Two Important Studies Polemonium viscosum (alpine skypilot) and bumblebees (Galen, 1996) Ipomopsis aggregata (scarlet gilia) and hummingbirds (Campbell et al., 1997)

48. Experiment Results Mean corolla tube width Visits/ flower/ hr.

49. Experiment Results Mean corolla tube width Visits/ flower/ hr. Wider Flowers = More Pollen Export

50. Experiment Results Mean corolla tube width Visits/ flower/ hr. Optical Density More redLess red Wider Flowers = More Pollen Export Seed set/ flower

51. Experiment Results Mean corolla tube width Visits/ flower/ hr. Optical Density More redLess red Wider Flowers = More Pollen Export Seed set/ flower Redder Flowers = More Seed

52. Conclusions Floral traits can determine level of pollinator attraction Pollinator preference caused plant reproductive success differences

53. Reproductive isolation in columbine Aquilegia pubescens Aquilegia formosa

54. Reproductive isolation in columbine Aquilegia pubescens Aquilegia formosa Note - viable hybrids from hand pollination

55. Aquilegia pubescens Aquilegia formosa

56. Aquilegia pubescens Aquilegia formosa

57. Experimental Design (Fulton and Hodges, 1999)

58. Results Hummingbirds almost always visit A. formosa

59. Results Hummingbirds almost always visit A. formosa Hawkmoths always visit A. pubescens

60. Conclusion Pollinator preference based on corolla morphology resulted in reproductive isolation

61. Any problems with this study?

62. No hybrids in array - not a complete test of pollinator preference

63. Any problems with this study? No hybrids in array - not a complete test of pollinator preference Need to show that hybrids attract mix of pollinator types

64. Any problems with this study? No hybrids in array - not a complete test of pollinator preference Need to show that hybrids attract mix of pollinator types

65. Are sympatric (overlapping distribution) in CA

66. Viable hybrids made from hand-pollinations

67. Are sympatric (overlapping distribution) in CA Viable hybrids made from hand-pollinations No hybrids seen under natural conditions

69. Results % of total visits made by bees

70. Conclusion Prove that corolla traits can determine type of pollinator attracted Pollinator preference can contribute to divergence of angiosperms through reproductive isolation

71. Lecture Overview Vascular plant diversity Modes of angiosperm speciation Pollination modes and angiosperm diversification Experiments: pollinator-mediated selection on floral traits Conclusions

72. Summary Animal-pollination mode is correlated with diversification of angiosperms Pollinator preferences can drive floral trait evolution Floral trait evolution in response to pollinator preferences can lead to reproductive isolation (= speciation) Pollinators have contributed to diversification of angiosperms

74. Archaeofructus