= appearance of wings. Once it appears it stays

1. A A A C C C B B B = appearance of wings. Once it appears it stays 1 3 2 On which tree are wings an apomorphy? On which tree are wings a synapomorphy uniting taxa A and C?

2. Bacteria & Archae

3. Bacteria & Archae • Wildly diverse • ~ 500 species in your mouth alone • Abundant (numerous) • 1012 on your skin; 1014 in G. I. tract; 1 teaspoon of soil contains billions • Ubiquitous • O2 free mud; salt flats; boiling hot springs; bedrock 1500 m deep; 10 km beneath ocean’s surface; 0° - 121° C

4. 2/3 major evolutionary lineages

5. Unifying features • Bacteria & Archae • Unicellular • lack a membrane-bound nucleus • Bacteria • Cell walls of peptidoglycan (forms tough, rigid sheets); distinct protein-making machinery • Archaea • Cell walls of polysaccharides (starches); protein-making machinery like Eukarya

6. Average Prokaryotic (Bacteria or Archaea) Cell

7. Some cause disease = pathogenic • Robert Koch (late 1800’s): “bacteria are responsible for infectious disease” • Developed 4 postulates to develop causative link between bacteria & disease • Germ theory of disease • Others are major sources of antibacterial (antibiotic) compounds • Cubist pharmaceuticals

8. Themes in diversification • Morphological diversity • Metabolic diversity

9. Morphological Diversity • Size • Shape • mobility

10. Morphological • Cell wall components are different • Lots of peptidoglycan; no outer membrane • Little peptidoglycan; outer membrane present • Species with outer membrane tend to be pathogenic • Confers increased resistance to desiccation & removal

11. Morphological • Common to ALL: • Haploid (all mutations are “visible to selection”) • Reproduce by fission (1 -> 2 daughter cells; vertical gene transfer) • Like mitosis: daughter cell is an exact copy of parent cell • Capable of conjugation (horizontal/lateral gene transfer) • Transfer plasmids (parasitic genomes) &sometimes their own genes via conjugation tubes • Wildly promiscuous

12. Incredible Metabolic diversity • Harnessing ATP (energy): • Phototrophs use light energy • Organotrophs use organic molecules (with high PE) with or without O2 • Lithotrophs use inorganic molecules (with high PE) • Building complex Carbon molecules: • Heterotrophs acquire from other organisms • Autotrophs make their own (using CO2, CH4)

13. Metabolic diversity

14. Potential bioremediators • Aside: Virtually ALL living things rely on O2 (aerobic) for harnessing energy (ATP) • However, many bacteria are anaerobic • At polluted sites, decomposition is slow because: • usually low in O2 (anoxic) • Pollutants are rarelygood food sources • Fertilize site to speed bacterial growth • “Seed” site with additional bacteria who thrive in low O2 (anaerobes) or can eat/use pollutants

15. Extremophiles are useful • As teachers: • Some live @ 0° C, some @ 121° C, 10 km deep • How do they withstand pressure and heat (we would implode)? • What enzymes do they have that can function at such temps (most disintegrate)? • As research assistants: • Our commercial DNA polymerase comes from a bacteria living in Yellowstone hot springs

16. Responsible for global changes • 4.5 --> 2.2 Bya: no free 02 • 2.7 Bya: Photosynthetic Cyanobacteria appear • Begin producing 02 as byproduct! • 2.4 - 2.2 Bya: Fossil and geological record indicate rise in oceanic O2 • 2.1 Bya: Organisms begin using O2 to make energy; Multicellularity evolves • O2 is a super-efficient energy producer • Organismal metabolism can be higher, growth can occur faster

17. Participants in Nitrogen cycle • Aside: Nitrogen (N) is necessary for anything with DNA and proteins = ALL save viruses • Most organisms cannot use N2 (us, green plants, fungi) • Some bacteria can trap N2; they make it available to the rest of us (nitrogen fixation) • Produce Ammonia (NH3) or nitrate (NO3-) • Live in close association with plants. Trade Nitrogen for food

18. Involved in Nitrate pollution • 2 population explosions • Fertilize crops • NH3 fert. Is used by bacteria in groundwater & soil • They release NO3- & NO2- as waste products • Contaminate drinking water • Cyanobacteria & algae use NO3- as food (PE) • Die, sink, & aerobic decomposers eat them (PE) • O2 depletion

19. Bacterial lineages

20. Many are commensal or mutualistic • Vitamin K • E. coli make the stuff & use it in their metabolism • We use it to construct blood clotting proteins

21. Many are pathogenic * Some are only pathogenic when they escape from their normal environment

22. Bacterial lineages • Chloroplasts • Mitochondria

23. How did Endomembrane system develop from prokaryotes? Invagination of plasma membrane Nuclear envelope ER Golgi Transport vessicles

24. How did other organelles develop? Cooperating prokaryotes Endosymbionts Mitochondria Chloroplasts Only organelles with: Separate genome replication & transcription machinery Reproduction via fission, independent of cell cycle Double membrane

25. Heterotrophic eukaryote engulfs cyanobacteria Bacteria evolves into chloroplast

26. Land Plants Chloroplasts evolve different pigments Eukaryote gives up ingestion; uses chloroplasts to produce food = autotrophic eukaryotes. Descendents evolve into land plants

27. Another heterotrophic eukaryote ingests an autotrophic eukaryote (Green algae)

28. Tremendous diversity in small, often single-celled Protists

29. Can we map some unifying traits?