1. The Diversity of Life I. An Overview

2. The Diversity of Life I. An Overview A. Classifying Organisms

3. The Diversity of Life I. An Overview A. Classifying Organisms Initially, using a Platonic, typological concept, Linnaeus and others created a nested, hierarchical system.

4. The Diversity of Life I. An Overview A. Classifying Organisms Initially, using a Platonic, typological concept, Linnaeus and others created a nested, hierarchical system. Evolution explained this nested pattern as a consequence of descent from common ancestors.

5. The Diversity of Life I. An Overview A. Classifying Organisms Initially, using a Platonic, typological concept, Linnaeus and others created a nested, hierarchical system. Evolution explained this nested pattern as a consequence of descent from common ancestors. Modern biologists view the classification system as a means of showing the phylogenetic relationships among groups.

6. The Diversity of Life I. An Overview A. Classifying Organisms Initially, using a Platonic, typological concept, Linnaeus and others created a nested, hierarchical system. Evolution explained this nested pattern as a consequence of descent from common ancestors. Modern biologists view the classification system as a means of showing the phylogenetic relationships among groups. Genetic relatedness should be the basic for biological classification... Genus Felis Genus Panthera Family Felidae * *

7. The Diversity of Life I. An Overview A. Classifying Organisms B. Kingdoms

8. The Diversity of Life I. An Overview A. Classifying Organisms B. Kingdoms Phylogenetic analysis revealed that the "Monera" were an incredibly diverse group genetically. Also, one subgroup - the Archea, were more similar to Eukaryotes than to the other group of prokaryotes (the 'Eubacteria').

9. The Diversity of Life I. An Overview A. Classifying Organisms B. Kingdoms Phylogenetic analysis revealed that the "Monera" were an incredibly diverse group genetically. Also, one subgroup - the Archea, were more similar to Eukaryotes than to the other group of prokaryotes (the 'Eubacteria'). This required a new way of looking at the most fundamental groupings of life - and the introduction of a new term: Domains

10. The Diversity of Life I. An Overview A. Classifying B. Kingdoms C. Domains

11. The Diversity of Life I. An Overview A. Classifying B. Kingdoms C. Domains Curiously, the very root of life may be invisible to genetic analysis. Bacteria transfer genes by division (to 'offspring'), but they also transfer genes "laterally" to other living bacteria. This makes reconstructing bacterial phylogenies difficult.

12. The Diversity of Life I. An Overview A. Classifying B. Kingdoms C. Domains Also, early evolution involved bacterial symbioses and gene sharing between hosts and symbionts

13. The Diversity of Life I. An Overview A. Classifying B. Kingdoms C. Domains So, reconstructing the patterns of relatedness among these ancient life forms is difficult.

14. The Diversity of Life I. An Overview A. Classifying B. Kingdoms C. Domains - "Ring of Life" hypothesis (2004)

15. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms

16. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms4.0 bya: Oldest Rocks

17. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms4.0 bya: Oldest Rocks3.5 bya: Oldest Fossils

18. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms4.0 bya: Oldest Rocks3.5 bya: Oldest Fossils Stromatolites - communities of layered 'bacteria'

19. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms4.0 bya: Oldest Rocks3.4 bya: Oldest Fossils 2.3-2.0 bya: Oxygen in Atmosphere

20. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms4.0 bya: Oldest Rocks3.4 bya: Oldest Fossils 2.3-2.0 bya: Oxygen 1.8 bya: first eukaryote

21. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms4.0 bya: Oldest Rocks3.4 bya: Oldest Fossils 2.3-2.0 bya: Oxygen 1.8 bya: first eukaryote 0.9 bya: first animals

22. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms4.0 bya: Oldest Rocks3.4 bya: Oldest Fossils 2.3-2.0 bya: Oxygen 1.8 bya: first eukaryote 0.9 bya: first animals 0.5 bya: Cambrian

23. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms4.0 bya: Oldest Rocks3.4 bya: Oldest Fossils 2.3-2.0 bya: Oxygen 1.8 bya: first eukaryote 0.9 bya: first animals 0.5 bya: Cambrian0.24 bya:Mesozoic

24. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms4.0 bya: Oldest Rocks3.4 bya: Oldest Fossils 2.3-2.0 bya: Oxygen 1.8 bya: first eukaryote 0.9 bya: first animals 0.5 bya: Cambrian0.24 bya:Mesozoic0.065 bya:Cenozoic

25. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms4.0 bya: Oldest Rocks3.4 bya: Oldest Fossils 2.3-2.0 bya: Oxygen 1.8 bya: first eukaryote 0.9 bya: first animals 0.5 bya: Cambrian0.24 bya:Mesozoic0.065 bya:Cenozoic 4.5 million to present (1/1000th of earth history)

26. The Diversity of Life I. An Overview D. Timeline 4.5 bya: Earth Forms4.0 bya: Oldest Rocks3.4 bya: Oldest Fossils 2.3-2.0 bya: Oxygen 1.8 bya: first eukaryote 0.9 bya: first animals 0.5 bya: Cambrian0.24 bya:Mesozoic0.065 bya:Cenozoic 5 million to present for 1/2 of life's history, life was exclusively bacterial.... what were they doing? Spheres, rods, and spirals were all they could come up with?? Let's look...

27. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria'

28. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria'

29. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms.

30. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. A. Oxygen Demand all eukaryotes require oxygen.

31. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. A. Oxygen Demand all eukaryotes require oxygen. bacteria show greater variability: - obligate anaerobes - die in presence of O2 - aerotolerant - don't die, but don't use O2 - facultative aerobes - can use O2, but don't need it - obligate aerobes - require O2 to live

32. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. A. Oxygen Demand all eukaryotes require oxygen. bacteria show greater variability: - obligate anaerobes - die in presence of O2 - aerotolerant - don't die, but don't use O2 - facultative aerobes - can use O2, but don't need it - obligate aerobes - require O2 to live represents an interesting continuum, perhaps correlating with the presence of O2 in the atmosphere.

33. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories:

34. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories: - chemolithotrophs: use inorganics (H2S, etc.) as electron donors for electron transport chains and use energy to fix carbon dioxide. Only done by bacteria.

35. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories: - chemolithotrophs: use inorganics (H2S, etc.) as electron donors for electron transport chains and use energy to fix carbon dioxide. Only done by bacteria. - photoheterotrophs: use light as source of energy, but harvest organics from environment. Only done by bacteria.

36. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories: - chemolithotrophs: use inorganics (H2S, etc.) as electron donors for electron transport chains and use energy to fix carbon dioxide. Only done by bacteria. - photoheterotrophs: use light as source of energy, but harvest organics from environment. Only done by bacteria. - photoautotrophs: use light as source of energy, and use this energy to fix carbon dioxide. bacteria and some eukaryotes.

37. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories: - chemolithotrophs: use inorganics (H2S, etc.) as electron donors for electron transport chains and use energy to fix carbon dioxide. Only done by bacteria. - photoheterotrophs: use light as source of energy, but harvest organics from environment. Only done by bacteria. - photoautotrophs: use light as source of energy, and use this energy to fix carbon dioxide. bacteria and some eukaryotes. - chemoheterotrophs: get energy and carbon from organics they consume. bacteria and some eukaryotes.

38. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. B. Nutritional Categories: - chemolithotrophs: use inorganics (H2S, etc.) as electron donors for electron transport chains and use energy to fix carbon dioxide. Only done by bacteria. - photoheterotrophs: use light as source of energy, but harvest organics from environment. Only done by bacteria. - photoautotrophs: use light as source of energy, and use this energy to fix carbon dioxide. bacteria and some eukaryotes. - chemoheterotrophs: get energy and carbon from organics they consume. bacteria and some eukaryotes.

39. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. C. Their Ecological Importance

40. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. C. Their Ecological Importance - major photosynthetic contributors (with protists and plants)

41. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. C. Their Ecological Importance - major photosynthetic contributors (with protists and plants) - the only organisms that fix nitrogen into biologically useful forms that can be absorbed by plants.

42. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. C. Their Ecological Importance - major photosynthetic contributors (with protists and plants) - the only organisms that fix nitrogen into biologically useful forms that can be absorbed by plants. - primary decomposers (with fungi)

43. The Diversity of Life I. An Overview II. An Overview of 'The Bacteria' The key thing about bacteria is their metabolic diversity. Although they didn't radiate much morphologically (spheres, rod, spirals), they DID radiate metabolically. As a group, they are the most metabolically diverse group of organisms. C. Their Ecological Importance - major photosynthetic contributors (with protists and plants) - the only organisms that fix nitrogen into biologically useful forms that can be absorbed by plants. - primary decomposers (with fungi) - pathogens