Transcript A GENERALIZED HISTORY OF EARTH

A GENERALIZED
HISTORY OF EARTH
TIMES
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This can be done several ways
I choose to break Earth’s history into
nine time periods
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~~5 billion years
- 4.6 billion years
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Extrapolation for the
most part
Formation of solar
system—
accumulation of
space trash
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4.6 billion years
-3.8 billion years
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Heating and melting of
earth
Out-gassing; early
atmosphere
Segregation of and
cooling of entire Earth
Early crust
Early seas
Beginnin of Plate
Tectonics
Life—single cell,
anaerobic, prokaryotic,
bacteria
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3.8 billion years
2.5 billion years
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Seas, freshsalty
Life – earliest plants,
prokaryotic,
photosynthesis
Atmosphere, more
O, less CO2
Photosynthesis (within plant cell)
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Energy (radiant)
CO2  C(in tissues) + O2
Accumulation of the Iron
Formations
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2.5 billion years
1.7 billion years
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Some critical level of
oxygen 
ppt of iron oxides
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Seas lose their Fe
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Generalized reaction
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Not ballanced or proper oxidation states
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Fein solution + O2  FeO.nH2O
ppt
Sexual reproduction!!!!!
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1.7 billion years
540 million years
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Eukaryotic cells!
Life forms go nuts
Seas and atmosphere
approach modern
compositions
Importance of sexual vs.
asexual reproduction
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Asexual (prokaryotic life) like a clone –
like-like-like-like-like-like-like
Sexual (eukaryotic life) exchange and
mixing of genes – great variability
unlike-ikulen-different-efefident-tenidffee
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540 million years
245 million years
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Hard parts!!
Plate movements
Fish
Land plants
Amphibians
Seed ferns and scale
trees
reptiles
Hard parts
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Shell – CaCO3
Kytton – complex, organic, C-bearing
Bone – CaPO4
Teeth – CaPO4
Scales -Cellulose (sort of) – complex, organic,
C-bearing
Hard parts -- importance
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Protection and structure
Key to fossilization
Hence, key to information preservation
Shells of various sorts
Fish have bone and teeth
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245 million years
66 million years
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Great extinction
Plate movements 1
Cone bearing plants
Dinosaurs
Mammals
Plate movements 2
Birds
Flowering plants
A GREAT EXTINCTION AT
245 MILLION YEARS
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BIO
BIO
BIO
BIO
BIO
BIO
BIO
BIO
FAMILY
FAMILY
FAMILY
FAMILY
FAMILY
FAMILY
FAMILY
FAMILY
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marine
marine
marine
marine
marine
marine
marine
marine
marine
marine
invertebrates
invertebrates
invertebrates
invertebrates
invertebrates
invertebrates
invertebrates
invertebrates
invertebrates
invertebrates
PLATE CONFIGERATION AT
ABOUT 180 MILLION YEARS
Some new players in the
game of life
PLATE CONFIGERATION AT
ABOUT 120 MILLION YEARS
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66 million years
1.6 million years
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Extinction
Earliest horse
Grasses
Earliest hominids
A MAJOR EXTINCTION AT
66 MILLION YEARS
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BIO
BIO
BIO
BIO
BIO
BIO
BIO
BIO
FAMILY
FAMILY
FAMILY
FAMILY
FAMILY
FAMILY
FAMILY
FAMILY
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DINOSAURS
Three new players in the
game of life
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1.6 million years
1,200 years
NOW
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The ice ages
The Ice Ages
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A time of climatic vairation
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Four times  cold
Four times  ice caps and glaciers
Spaced by  warm (like now)
Including warm before and now
AND CAME THE ICE AND
COVERED ~25% OF THE LAND