Bacteria Evolution

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Bacteria Evolution and Classification
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Bacteria Evolution

• Believed to be 1st oldest life on earth
• 1) Simplest cell structure
• 2) Oldest fossils known (3.5 byo)
• Adapted to most environments

Oldest Fossil Pictures
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Archaebacteria

• Live in extreme environments
• Offer glimpse of early earth
• 3 Main Categories
• 1) Methanogens
• 2) Halophiles
• 3) Thermophiles

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Archaebacteria

• 1) Methanogens
• Anaerobic
• Produce methane gas as a waste product
• Habitat Swamps, sewage, digestive tract

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Archaebacteria

• 2) Thermophiles
• Heat and acid loving bacteria
• Habitat Deep sea vents, volcanoes, hot springs
  (230F)

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Archaebacteria

• 3) Halophiles
• Bacteria which thrive in areas of high salt
  concentration
• Salt normally dehydrates organisms
• Use salt to make energy

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Archaebacteria The 6th Kingdom?
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Eubacteria (Modern Bacteria)

• Common to most environments on Earth
• Often identified by Gram Stain test
• Gram negative stains pink (harder to treat
  because of thick capsule)
• Gram positive stains purple (easier to treat)
• Treatments differ depending upon results

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Gram Stain Overview
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Eubacteria (Modern bacteria)

• Cyanobacteria autotrophic bacteria
• Create oxygen for life on earth
• Created Earths ozone layer to block ultraviolet
  radiation (UV) from the sun
• Oxygen (O2) is recombined into ozone (O3) in the
  stratosphere
• Allows life to live on land

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Pollution Alert!

• The Problem The ozone layer is thinning!
• The Cause Manmade chemicals (CFCs) from industry
• CFCs break apart ozone molecules
• More UV radiation strikes Earths surface
• The Solution Reduce CFC use plant more trees

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Ozone Layer Harm Sources
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Ozone layer
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O3 destroyed by chlorine from CFCs
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Gram Positive or Gram Negative?
Gram Negative
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Quick Review

• Bacteria occupy most habitats
• Monerans were 1st life on Earth
• Cyanobacteria were 1st to make oxygen