Transcript Earth: An Ever changing planet

Recording natural history
Break down of time
• Different periods of Earth’s
history are broken into periods of
time
– just like a year is broken into
months, weeks, days and hours
• Earth history is broken into eons,
eras, periods, epochs
Eons – Billions of years
• Haden: Earth before life evolved
3.5 to 3.9 Billion years ago
• Achaean: Earth with only prokaryotic cells
– 3.9 to 2.5 Billion years ago
• Proterozoic: Current Eon
– 2.5 BYA to present
How time periods distinguished
• Major geological events: The
movement of tectonic plates to
form continents and supercontinents
• Changes in climate: a change from
an ice ace to a warming period
• Mass extinctions or explosions:
Changes in the types of life forms
on earth
Haden Eon 4.5-3.9 BYA
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The first 13% of the Earth’s history
Earth is a solid lifeless planet
No liquid water, little O2 in the atmosphere
Relative to a calendar year:
Jan 1st – Feb. 25th
Achaean Eon 3.9-2.5 BYA
• Earth has a crust & ocean
• Life forms in the sea
• Prokaryotes including photosynthetic blue-green
algae & later bacteria
• Feb. 25th - April 17th
Proterozoic Eon: Precambrian Era
2.5 BYA – 540MYA
• Super continent Rodinia
• 21% O2 in Atmosphere
• First Eukaryotic cell & sexual reproduction
– July 13th
• First Multicellular organism (seaweed/algea)
– Aug 31st
Review of
Earth’s first
3.9 Billion
years
Haden
lifeless Earth
Proterozoic
Eukaryotic life,
Achaean
multicellular plants,
First plants & soft
Prokaryotic life
bodied animals in
Little O2
oceans later vascular
plants fish,
arthropods in ocean
Insects, amphibians
& reptiles on land
Paleozoic Era
From the Cambrian exposition to
Permian extinction
Paleozoic Era
Cambrian Explosion 540-490 MYA
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2 continents mild climate
All life in ocean
Sponges & coral
Then mollusks (clams)
Later arthropods (trilobites)
Finally chordates – pre-vertebrate ancestors
Nov. 17 - Nov. 21st
Paleozoic Era
Ordovician Period 490-443 MYA
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More Continents
First vertebrates – armored fish
First plants & invertebrates on land
Nov. 21st – Nov. 24th
Silurian Period 443-417 MYA
• Most continents are near equator
First: nautilus, jawed fish, shark, lungfish
Lots of arthropods
more complex plants on land (vascular)
Nov 24th – Nov. 27th
Paleozoic Era
Devonian Period 417-354
Paleozoic Era
• Europe & N. America at equator & S American &
Africa over S. pole
• Warm & moist
• First: air breathing Arthropods
• First: insects (beetles), amphibians, seed plants (ferns)
• Nov. 27th - Dec 1st
Paleozoic Era
Carboniferous Period 354-290 MYA
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First swampy & warm then cold glaciers
Oceans: armored fish extinct
greater diversity of fish etc.
Land: Giant insects, first reptiles
Dec 1nd – Dec 6th
Paleozoic Era
Permian Period: 290-248
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Supercontinent Pangaea – all climate zones
Glaciers & deserts
Mass extinction 99% of all life gone
Modern insects, fewer amphibians, many reptiles
Dec. 6th - Dec 10th
Mesozoic Era
The rise and fall of dinosaurs
Triassic Period 248-206 MYA
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Pangaea covers ¼ Earth’s surface
Warm and dry climate
On Land: 1st small dinosaurs
Plants: Ferns, ginkgoes, & conifers
In ocean: 1st reptiles
Dec. 10- Dec. 14
Mesozoic Era
Mesozoic Era
Jurassic Period 206-144 MYA
• Pangaea begins to break apart
• Dinosaurs dominate land and sea
• First bird
• Early amphibians go extinct, replaced
by frogs & salamanders
• First mammals (small shrew like)
• Dec. 14th - Dec. 19th
Mesozoic Era
Cretaceous Period 144-65 MYA
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Sea levels rise no ice at poles
Large dinosaurs dominate
most modern insects
First flowering plants
Ends with mass extinction of Dinosaurs
Dec. 19th – Dec 25th
Cenozoic Era
Paleocene Epoch 65-55 MYA
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Mammals diversify first just marsupials
Inland seas dry up Australia breaks free
Later placental mammals
First dogs & cats
Dec 25th
Oligocene Epoch 34-24 MYA
• Lots a tectonic plate movement temperate
climate
• Grass land expand forest decline
• First primate
• Dec. 28
Cenozoic Era
Miocene Epoch 24-5 MYA
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Climate cools
Half of modern mammals exist
Many modern bird groups
First: apes
Dec 29th – Dec. 31st 3PM
Cenozoic Era
Pliocene Epoch 5-1.8 MYA
• Alps rise & central America formed
• Camels, horses, & giant ground sloths in N.
America
• Australopithecines – 1st human ancestor
• Dec 31st 3:00 PM – 10 PM
Pleistocene Epoch 1.8 M- 10,000
• Great ice age – 30% earth covered
in ice
• Wooly mammoths & saber-tooth
cat go extinct
• homo habilis
• Dec. 31st: 10PM – 11:48 PM
Holocene Epoch 10 TYA - today
• Glaciers retreat, sea levels rise, deserts form
• 1st Humans to modern civilizations
• The world as we know it
First monkeyFirst human
Last Dinosaurs
First bird
Flowering Plants
First Mammals
First Dinosaurs
Review of last 240
Million years
Review
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What was the surface of the earth life for most of the
Haden Era?
During which era did multicellular life evolve?
Which is a shorter period of time and eon or an era?
During which period did flowering plants evolve?
When did the first birds evolve?
What were the first vertebrates?
When did the first air breathing arthropods evolve.
What was the name of the supercontenent formed
during the Permian?