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

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

4. Species richness

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

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

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

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

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

10. Hawaiian silverswords

11. 4 th mass extinction 210 mya: ~65% of species 5 th mass extinction 65 mya: ~76% of species Extraterrestrial impact or volcanism?

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

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

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

17. Classifying the diversity of life Systematics

18. Classifying the diversity of life Systematics Taxonomy Phylogenetics

19. Bluebells…

20. Taxonomy Linnaeus (1700s) –System of classification based on morphological similarity

21. Taxonomy Linnaeus (1700s) –System of classification based on morphological similarity –Binomial nomenclature

22. Taxonomy Linnaeus (1700s) –System of classification based on morphological similarity –Binomial nomenclature –Hierarchical classification

23. Binomial nomenclature Homo GenusSpecies sapiens Capitalize Italicize or underline

24. Hierarchical classification Kingdom: Phylum: Class: Order: Family: Genus: Species:

25. Hierarchical classification Kingdom:Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Genus:Homo Species: H. sapiens

26. Hierarchical classification Kingdom:Animalia Phylum: Arthropoda Class: Insecta Order: Diptera Family: Muscidae Genus:Musca Species: M. domestica

27. Hierarchical classification Kingdom:Plantae Phylum: Anthophyta Class: Monocotyledonae Order: Poales Family: Poaceae Genus:Zea Species: Z. mays

28. Hierarchical classification Kingdom:Plantae Phylum: Anthophyta Class: Monocotyledonae Order: Asparagales Family: Orchidaceae Genus:Vanilla Species: V. planifolia

29. Phylogenetics Classification of organisms according to their evolutionary relationships

30. Phylogenetics Classification of organisms according to their evolutionary relationships A phylogeny is the history of decent of a group of organisms from their common ancestor

31. Ancestor Sp. 1Sp. 2Sp. 3

33. Ancestor Sp. 1Sp. 2Sp. 3

34. Ancestor Sp. 1Sp. 2Sp. 3 Derived traits Ancestral trait

35. Ancestor Sp. 1Sp. 2Sp. 3 Tail stub SHARED CHARACTER

36. Ancestor Sp. 1Sp. 2Sp. 3 Tail stub Tail motor control SHARED DERIVED CHARACTER

37. Ancestor Sp. 1Sp. 2Sp. 3 Prehensile control Tail stub appears Tail motor control DERIVED CHARACTER

38. JawsLimbsHairLungsTailShell 000000 110101 111100 111110 100100 100000 111110 Lamprey Turtle Cat Gorilla Lungfish Trout Human Taxon Traits (Characters)

40. Homologs Features that have descended from a common ancestral feature

41. Homologs Features that have descended from a common ancestral feature Use homology to determine phylogenetic relationships

42. Homologs Traits can be… Morphological Developmental Behavioral Molecular

43. Homologous features

44. Difficulty Traits change with evolution

49. More difficulties… Convergent evolution

50. More difficulties… Convergent evolution –Similar environments shape features that have different ancestral origins to look very much alike

51. Arm bones are homologous BUT wings are the result of convergent evolution

52. Cactus and euphorbs

53. More difficulties… Parallel evolution

54. More difficulties… Parallel evolution –Similar developmental processes may make traits in distantly related organisms look similar, even though those traits did not come from a shared ancestor

56. More difficulties… Evolutionary reversals

57. More difficulties… Evolutionary reversals –A derived trait may revert back to its ancestral state

58. Ancestor—Toothy frog Sp. 1Sp. 2Sp. 3 Loss of teeth Teeth regained

59. More difficulties… Convergent evolution Parallel evolution Evolutionary reversals Traits that are similar due to these processes are called homoplastic traits

60. Homologous trait versus Homoplastic trait Same because of descent from common ancestor Same because shaped by similar environments

61. Homologous trait versus Homoplastic trait Used to build phylogenetic relationships Not used to build phylogenetic relationships

62. Principle of parsimony Choose the simplest hypothesis capable of explaining the pattern.

63. Principle of parsimony Choose the simplest hypothesis capable of explaining the pattern. Descent from a common ancestor is much simpler than invoking homoplasies.

64. Principle of parsimony …think of it as the path of least resistance It is “easier” to inherit a trait than to build a new one.

65. Principle of parsimony The null hypothesis: this trait was inherited from a common ancestor The alternative hypothesis: this trait was built by natural selection

66. Modern taxonomy

67. Biological species Versus “taxonomic” species

68. Modern taxonomy Taxonomic groups should reflect evolutionary relationships

69. Modern taxonomy Taxonomic groups should reflect evolutionary relationships Taxonomic groups should be monophyletic –They should contain all the descendents of a particular ancestor, and no others

70. Monophyletic

72. Evolutionary Tree extreme thermophiles halophiles methanogens cyanobacteria ARCHAEBACTERIA PROTISTANS FUNGI PLANTS ANIMALS club fungi sac fungi zygospore- forming fungi echino- derms chordates annelids mollusks flatworms sponges cnidarians flowering plants conifers horsetails lycophytes ferns bryophytes sporozoans green algae amoeboid protozoans slime molds ciliates red algae brown algae chrysophytes cycads ginkgos rotifers arthropods round- worms chytrids oomycotes euglenoids dinoflagellates Gram-positive bacteria spirochetes chlamydias proteobacteria ? crown of eukaryotes (rapid divergences) molecular origin of life EUBACTERIA parabasalids diplomonads (e.g., Giardia) (alveolates) (stramenopiles) chlorophytes kinetoplastids extreme (e.g., Trichomonas) Figure 19.21 Page 321

73. Five Kingdoms BacteriaProtistsPlantsFungiAnimals Earliest organisms

74. Three domains Bacteria Earliest organisms ArchaeaEukarya