1. History and Diversity of Life
I. Origin of Life Hypotheses

2. A. The Early Earth and Earth History
4.5 bya: Earth Forms
Graviational sorting of materials…heavy to the core, gases released under pressure…

3. The Early Earth and Earth History
- Earliest Atmosphere - probably of volcanic origin
Gases produced were probably similar to those released by modern volcanoes (H2O, CO2, SO2, CO, S2, Cl2, N2, H2) and NH3 and CH4

4. A. The Early Earth and Earth History
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks

5. A. The Early Earth and Earth History
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils
Stromatolites - communities of layered 'bacteria'

6. A. The Early Earth and Earth History
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils
Putative microfossil bacteria from Australia that date to 3.4 by

7. A. The Early Earth and Earth History
bya: Oxygen in Atmosphere
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils

8. A. The Early Earth and Earth History
bya: Oxygen
1.8 bya: first eukaryote
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils

9. A. The Early Earth and Earth History
bya: Oxygen
1.8 bya: first eukaryote
0.9 bya: first animals
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils

10. A. The Early Earth and Earth History
bya: Oxygen
1.8 bya: first eukaryote
0.9 bya: first animals
0.5 bya: Cambrian
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils

11. A. The Early Earth and Earth History
bya: Oxygen
1.8 bya: first eukaryote
0.9 bya: first animals
0.5 bya: Cambrian
0.24 bya:Mesozoic
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils

12. A. The Early Earth and Earth History
bya: Oxygen
1.8 bya: first eukaryote
0.9 bya: first animals
0.5 bya: Cambrian
0.24 bya:Mesozoic
0.065 bya:Cenozoic
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils

13. A. The Early Earth and Earth History
4.5 million to present
(1/1000th of earth history)
bya: Oxygen
1.8 bya: first eukaryote
0.9 bya: first animals
0.5 bya: Cambrian
0.24 bya:Mesozoic
0.065 bya:Cenozoic
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks
3.4 bya: Oldest Fossils

14. B. The Formation of Biologically Important Molecules
- Oparin-Haldane Hypothesis (1924):
- in a reducing atmosphere, biomonomers would form spontaneously
Aleksandr Oparin
( )
J.B.S. Haldane
( )

15. B. The Formation of Biologically Important Molecules
- Oparin-Haldane Hypothesis (1924):
- in a reducing atmosphere, biomonomers would form spontaneously
- Miller-Urey (1953)
all biologically important monomers have been produced by these experiments, even while changing gas composition and energy sources

16. C. Acquiring the Characteristics of Life
Three Primary Attributes:
- Barrier (phospholipid membrane)
- Metabolism (reaction pathways)
- Genetic System

17. C. Acquiring the Characteristics of Life
1. Evolution of a Membrane
- form spontaneously in aqueous solutions

18. C. Acquiring the Characteristics of Life
Evolution of a Membrane
Metabolic Pathways
Evolution of a Genetic System
- conundrum... which came first, DNA or the proteins they encode?
DNA
RNA (m, r, t)
protein

19. C. Acquiring the Characteristics of Life
Evolution of a Membrane
Metabolic Pathways
Evolution of a Genetic System
- conundrum... which came first, DNA or the proteins they encode?
DNA
DNA stores info, but proteins are the metabolic catalysts...
RNA (m, r, t)
protein

20. C. Acquiring the Characteristics of Life
Evolution of a Membrane
Metabolic Pathways
Evolution of a Genetic System
- conundrum... which came first, DNA or the proteins they encode?
- Ribozymes
info storage AND
cataylic ability

21. C. Acquiring the Characteristics of Life
Evolution of a Membrane
Metabolic Pathways
Evolution of a Genetic System
- conundrum... which came first, DNA or the proteins they encode?
- Ribozymes
- Self replicating molecules
- three stage hypothesis

22. Stage 1: Self-replicating RNA evolves

23. (REPLICATION ENZYMES)
Stage 1: Self-replicating RNA evolves
RNA
m- , r- , and t- RNA
PROTEINS
(REPLICATION ENZYMES)
Stage 2: RNA molecules interact to produce proteins... if these proteins assist replication (enzymes), then THIS RNA will have a selective (replication/reproductive) advantage... chemical selection.

24. (REPLICATION ENZYMES)
DNA
Reverse transcriptases
m- , r- , and t- RNA
PROTEINS
(REPLICATION ENZYMES)
Stage 3: Mutations create new proteins that read RNA and make DNA; existing replication enzymes replicate the DNA and transcribe RNA.

25. Can this happen? Are their organisms that read RNA and make DNA?

26. Can this happen? Are their organisms that read RNA and make DNA?
yes - retroviruses....

28. (REPLICATION ENZYMES)
DNA
m- , r- , and t- RNA
Already have enzymes that can make RNA...
PROTEINS
(REPLICATION ENZYMES)
Stage 3: Mutations create new proteins that read RNA and make DNA; existing replication enzymes replicate the DNA and transcribe RNA.

29. (REPLICATION ENZYMES)
DNA
m- , r- , and t- RNA
Already have enzymes that can make RNA...
PROTEINS
(REPLICATION ENZYMES)
Stage 3: Mutations create new proteins that read RNA and make DNA; existing replication enzymes replicate the DNA and transcribe RNA.

30. (REPLICATION ENZYMES)
This is adaptive because the two-step process is more productive, and DNA is more stable (less prone to mutation).
DNA
m- , r- , and t- RNA
PROTEINS
(REPLICATION ENZYMES)
Stage 4: Mutations create new proteins that replicate the DNA instead of replicating the RNA...

31. (REPLICATION ENZYMES)
This is adaptive because the two-step process is more productive, and DNA is more stable (less prone to mutation).
DNA
And that's the system we have today....
m- , r- , and t- RNA
PROTEINS
(REPLICATION ENZYMES)
Stage 4: Mutations create new proteins that replicate the DNA instead of replicating the RNA...

32. D. Summary:
STEPS REQUIRED FOR THE SPONTANEOUS, NATURAL FORMATION OF LIFE, and the evidence to date:
1. Spontaneous synthesis of biomolecules - strong evidence; Miller-Urey experiments.
2. Polymerization of monomers into polymers (proteins, RNA, sugars, fats, etc.) - strong evidence;  Fox and Cairns-Smith experiments.
3. Formation of membranes - strong evidence; behavior of phospholipids in solution.
4. Evolution of metabolic systems - reasonable hypotheses, and genetic similarity in genes involved in particular pathways (suggesting gene duplication and subsequent evolution of new genes and elaboration of existing pathways)
5. Evolution of a genetic system - a reasonable hypothesis and significant corroborating evidence that it could happen. But no experimental evidence of the process evolving through all three steps.
6. How did these three elements (membrane, metabolism, genetic system come together?) a few untested hypotheses.

33. Diversity
Origin of Life
A Brief History of Life

34. I. A Brief History of Life
The Diversity of Life
I. A Brief History of Life
Introduction
B. Timeline
2.0 bya: first eukaryotes
bya: Oxygen
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks
3.5 bya: Oldest Fossils
Grypania spiralis – possibly a multicellular algae, dating from 2.0 by

35. I. A Brief History of Life
The Diversity of Life
I. A Brief History of Life
Introduction
B. Timeline
- Life was exclusively bacterial for ~40% of life’s 3.5 by history
- Ecosystems evolved with bacterial producers, consumers, and decomposers.
- Multicellular eukaryotic organisms evolved that use and depend on these bacteria

36. I. A Brief History of Life
The Diversity of Life
I. A Brief History of Life
Introduction
B. Timeline
0.065 bya: Cenozoic
0.7 bya: first animals
2.0 bya: first eukaryotes
bya: Oxygen
0.5 bya: Cambrian
0.24 bya:Mesozoic
4.5 bya: Earth Forms
4.0 bya: Oldest Rocks
3.5 bya: Oldest Fossils
For ~40% of life’s history, life was exclusively bacterial

37. Ecological Roles Played By Prokaryotes
ATMOSPHERE
N fixation
Photosynthesis
Respiration
BIOSPHERE
Energy harvest of animals and plants
Absorption
Decomposition
LITHOSPHERE

38. I. A Brief History of Life II. Classifying Life
The Diversity of Life
I. A Brief History of Life
II. Classifying Life
The Linnaean System
- a ‘nested’ hierarchy
based on morphology

39. I. A Brief History of Life II. Classifying Life
The Diversity of Life
I. A Brief History of Life
II. Classifying Life
The Linnaean System
Cladistics and Phylogenetic Systematics
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

40. I. A Brief History of Life II. Classifying Life
The Diversity of Life
I. A Brief History of Life
II. Classifying Life
The Linnaean System
Cladistics and Phylogenetic Systematics
The goal is to make a monophyletic classification system, in which descendants of a common ancestor are in the same taxonomic group.
NEW
HOMINIDAE
Genera:
Australopithecus
Homo
PONGIDAE
Pan
Gorilla
Pongo
OLD

41. I. A Brief History of Life II. Classifying Life
The Diversity of Life
I. A Brief History of Life
II. Classifying Life
The Linnaean System
Cladistics and Phylogenetic Systematics
The goal is to make a monophyletic classification system, in which descendants of a common ancestor are in the same taxonomic group.
OLD
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Class: Mammalia
Class: Aves

42. I. A Brief History of Life II. Classifying Life
The Diversity of Life
I. A Brief History of Life
II. Classifying Life
The Linnaean System
Cladistics and Phylogenetic Systematics
NEW

43. I. A Brief History of Life II. Classifying Life
The Diversity of Life
I. A Brief History of Life
II. Classifying Life
The Linnaean System
Cladistics and Phylogenetic Systematics
The goal is to make a monophyletic classification system, in which descendants of a common ancestor are in the same taxonomic group.
OLD

44. I. A Brief History of Life II. Classifying Life
The Diversity of Life
I. A Brief History of Life
II. Classifying Life
The Linnaean System
Cladistics and Phylogenetic Systematics
The goal is to make a monophyletic classification system, in which descendants of a common ancestor are in the same taxonomic group.
NEW

45. III. The Prokaryote Domains: Eubacteria and Archaea
Overview
Bacteria
Archaea
Eukarya
No nucleus
no nucleus
nucleus
no organelles
no organelles
organelles
peptidoglycan no
1 RNA Poly
several
F-methionine
methionine
Introns rare
present
common
No histones
histones
Circular X’some
Linear X’some

46. III. The Prokaryote Domains: Eubacteria and Archaea
Overview
1. Archaea
“Extremeophiles”
- extreme thermophiles: sulphur springs
and geothermal vents
- extreme halophiles: salt flats
“Methanogens”
Also archaeans that live in benign
environments across the planet.

47. III. The Prokaryote Domains: Eubacteria and Archaea
Overview
1. Archaea
2. Bacteria
- proteobacteria
- Chlamydias
- Spirochetes
- Cyanobacteria
- Gram-positive bacteria

48. III. The Prokaryote Domains: Eubacteria and Archaea
Overview
1. Archaea
2. Bacteria
These groups are very diverse genetically and metabolically. Their genetic diversity is represented by the “branch lengths” of the groups, showing how different they are, genetically, from their closest relatives with whom they share a common ancestor.

49. III. The Prokaryote Domains: Eubacteria and Archaea
Overview
B. Metabolic Diversity of the Prokaryotes
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.

50. III. The Prokaryote Domains: Eubacteria and Archaea
Overview
B. Metabolic Diversity of the Prokaryotes
1. Responses to Oxygen:
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

51. III. The Prokaryote Domains: Eubacteria and Archaea
Overview
B. Metabolic Diversity of the Prokaryotes
C. 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
endosymbionts with animals, protists, and plants

52. Bacteria still drive major dynamics of the biosphere

53. The Diversity of Life
I. Origin of Life Hypotheses
II. Classifying Life
III. The Prokaryote Domains: Bacteria and Archaea
IV. The Domain Eukarya

54. I. A Brief History of Life II. Classifying Life
The Diversity of Life
I. A Brief History of Life
II. Classifying Life
III. The Prokaryote Domains: Bacteria and Archaea
IV. The Domain Eukarya
A. Overview:
2.0 billion years of evolution
Very diverse
Unicellular, colonial, multicellular

55. - membrane bound nucleus - organelles - sexual reproduction and
IV. The Domain Eukarya
A. Overview:
- membrane bound nucleus
- organelles
- sexual reproduction and
meiosis

56. IV. The Domain Eukarya Overview: Origin of the Eukarya
1. Origin of Organelles

57. IV. The Domain Eukarya Overview: Origin of the Eukarya
1. Origin of Organelles

58. IV. The Domain Eukarya Overview: Origin of the Eukarya
C. Diversity of Eukarya

59. Parabasalida (Trichomonas)
Diplomonad (Giardia)
Parabasalida (Trichomonas)
IV. The Domain Eukarya
Overview:
Origin of the Eukarya
C. Diversity of Eukarya

60. Trypanosoma IV. The Domain Eukarya Euglena Euglenozoa Overview:
Origin of the Eukarya
C. Diversity of Eukarya
Euglena
Euglenozoa

61. Apicomplexans (Plasmodium) Ciliates (Paramecium)
Dinoflagellates
Apicomplexans (Plasmodium)
Ciliates
(Paramecium)
IV. The Domain Eukarya
Overview:
Origin of the Eukarya
C. Diversity of Eukarya
Alveolata

62. Diatoms IV. The Domain Eukarya Stramenopiles Brown Algae Overview:
Origin of the Eukarya
C. Diversity of Eukarya
Stramenopiles
Brown Algae

63. Radiolarians IV. The Domain Eukarya Foraminiferans Overview:
Origin of the Eukarya
C. Diversity of Eukarya
Foraminiferans
Rhizaria

64. IV. The Domain Eukarya Amoebozoa Overview: Origin of the Eukarya
C. Diversity of Eukarya
Amoebozoa

65. IV. The Domain Eukarya Red Algae Green Algae Plants Overview:
Origin of the Eukarya
Diversity of Eukarya
Archaeplantae
Red Algae
Green Algae
Plants

66. IV. The Domain Eukarya Overview: Origin of the Eukarya
Diversity of Eukarya
Archaeplantae

67. IV. The Domain Eukarya Opisthokonts Overview: Origin of the Eukarya
C. Diversity of Eukarya
Opisthokonts

68. IV. The Domain Eukarya FUNGI Chytrid zoospores flagella Overview:
Origin of the Eukarya
Diversity of Eukarya
Opisthokonts
FUNGI
Chytrid zoospores
flagella

69. IV. The Domain Eukarya Choanoflagellates Overview:
Origin of the Eukarya
Diversity of Eukarya
Opisthokonts
Choanoflagellates

70. IV. The Domain Eukarya ANIMALS Overview: Origin of the Eukarya
Diversity of Eukarya
Opisthokonts
ANIMALS