EARLY EARTH

1
EARLY EARTH and the ORIGIN OF LIFE
2
Major Episodes
Isotopes of carbon
3

• Life on Earth 3.5-4.0 billion years
• Prokaryotes 3.5 billion
• stromatolites
• Oxygen 2.7 billion
• Cyanobacteria
• Eukaryotes 2.1 billion
• Multicellular Eukaryotes 1.2 billion
• Animal Diversity Cambrian period
• Land plants 500 million

4
Cambrian Explosion
5

• THE ORIGIN OF
• LIFE
• Spontaneous
• generation
• Biogenesis
• Louis Pasteur

6
Miller Urey

• Primitive
• Atmosphere
• H2O
• H2
• CH4
• NH3
• Formation of organic monomers first
  step in origin of life

7

• RNA may have been the first self replicating
  genetic material.
• Replication ribozymes (RNA autocatalytic)
• Natural selection (genotype phenotype)

8
PROTOBIONTS aggregates of abiotically
produced molecules
liposome
9
RNA template for polypeptide formation
Polypeptides act as primitive enzymes that aid
replication of all RNA molecules,
including competing RNAs
10
FIVE KINGDOM SYSTEM
11
Kingdom Characteristics must know!
12
PROKARYOTESAND THE ORIGINS OF METABOLIC
DIVERSITY
13
PROKARYOTES
extremophiles
eubacteria
14
STRUCTURE FUNCTION

• Shape cocci (spherical), bacilli (rod), spirilla
  (helical)
• Diplo- (2), strepto- (chain), staphylo- (cluster)
• Peptidoglycan (modified sugars cross-linked by
  short polypeptides) in cell walls
• Gram stain Gram (simpler walls, thick
  peptidoglycan) Gram- (more complex, less
  peptidoglycan)
• Capsule protective layer outside wall, sticky
• Pili surface appendages

15
(No Transcript)
16
Motility flagella, spirochetes (corkscrew,)
slimy threads Taxis movement toward or away
from stimulus
17
ORGANIZATION REPRODUCTION

• Specialized membranes
• Nucleoid region
• Plasmids
• Binary fission

• Transformation
• Conjugation
• Transduction
• Endospores
• Antibiotics

18
(No Transcript)
19

• Nutritional Diversity
• Saprobes
• Parasites
• Metabolism of petroleum
• Nonbiodegradable (synthetic organic compounds)

• Nitrogen Metabolism
• Nitrogen fixation
• N2 ? NH4
• Cyanobacteria

Oxygen use Obligate aerobes Facultative
anaerobes Obligate anaerobes
20
(No Transcript)
21

• EXTREMOPHILES
• Methanogens
• Extreme halophiles (bacteriorhodopsin
• Extreme thermophiles

22
(No Transcript)
23
(No Transcript)
24
ECOLOGICAL IMPACT

• Decomposers
• Symbiosis
• Mutualism
• Commensalism
• Parasitism

• Pathogenic
• Kochs Postulates
• Exotoxins
• Endotoxins
• Bioremediation

25
(No Transcript)
26
THE ORIGINS OFEUKARYOTIC DIVERSITY
27
(No Transcript)
28
Characteristics

• Eukaryotic, unicellular, colonial, multicellular
• Nutrition aerobic, photoautotrophs,
  heterotrophs, mixotrophs
• Ingestive (protozoa), photosynthetic (algae),
  absorptive (fungus like)
• Motility flagella, cilia, psuedopodia
• Life cycles asexual (mitosis), sexual (meiosis
  syngamy), cysts
• Habitat aquatic (plankton) moist terrestrial
  areas, contractile vacuoles

29
EUGLENA - MIXOTROPH
30
EVOLUTIONARY TRENDS 1) Filamentous Cyanobacteria
specialized cells 2) Complex communities
species w/ metabolic specialties 3)
Compartmentalization within cells ? eukaryotes
ENDOSYMBIOSIS
31
PRIMARY SECONDARY ENDOSYMBIOSIS
32
(No Transcript)
33
(No Transcript)
34
(No Transcript)
35
(No Transcript)
36
Diplomonadida and Parabasala
lack mitochondria 
Giardia lamblia
Trichomonas vaginalis
37
 Euglenozoa 

• both photosynthetic and heterotrophic
  flagellates 

Euglena - mixotrophic
Trypanosoma African sleeping sickness
38
 Alveolata

• unicellular protists with subsurface cavities
  (alveoli) 
• Dinoflagellates red tides (deadly toxins)
  Gonyaulax
• Ciliates paramecium, stentor
• Apicomplexans all parasitic, plasmodium - malaria

39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
Stramenopila

• The stramenopile clade includes the water molds
• and the heterokont algae

Oomycota Water mold
Diatoms glass like cell walls
Chrysophytes Golden algae
Phaeophytes brown algae, Seaweeds (kelps)
43

• SEAWEEDS
• Structural and biochemical adaptations help
  seaweeds survive and reproduce at the oceans
  margins 
• Food source, thickening agents, agar  
• Some algae have life cycles with alternating
  multicellular haploid and diploid generations 

44
Rhodophyta Red algae lack flagella
Most abundant large algae in warm coastal
waters of tropical oceans
45
Chlorophyta

• Green algae and plants evolved from a common
  photoautotrophic ancestor
• Unicellular (chlamydomonas), colonial (volvox),
  filamentous (spirogyra), multicellular (ulva)
• Lichens

46
(No Transcript)
47
(No Transcript)
48
A diversity of protists use pseudopodia for
movement and feeding 
Rhizopoda amoebas, amoebic dysentery
49
Actinopoda (Heliozoan Radiolarians)
Foraminiferans calcium carbonate walls, limestone
fossils, Dover cliffs
50
Mycetozoa Slime molds have structural
adaptations and life cycles that enhance their
ecological roles as decomposers 
51
Plasmodial Slime Mold
52
(No Transcript)
53
FUNGI CHARACTERISTICS

• Eukaryotic
• Multicellular
• Heterotrophs (absorptive digestion outside
  body)
• Cell walls of chitin
• Classified by sexual stage (fruiting body)

54
Function obtaining food
55
Haustoria hyphae of parasitic fungi modified to
penetrate and absorb nutrients from host tissue
56
(No Transcript)
57
(No Transcript)
58
Example - Rhizopus
ZYGOMYCOTA
59
PENICILLIUM
ASCOMYCOTA
60
BASIDIOMYCOTA
61
LICHENS
MYCHORRHIZAE
Mutualistic Involve?
62
(No Transcript)