Geologic Time

1
Geologic Time Evolution

• Objectives The student understands
• 1) Geological time is used to understand the
  Earths past.
• 2) Biological Evolution explains the existence
  and diversity of life on Earth

2
Geology

• The Study of the Earths rocks.
• The formation, change, and composition
• Life History, plate Tectonics

3
Father of Modern Geology

• James Hutton

4
Uniformitarianism
5
The Age of the Earth

• 4.6 billion years old
• Life has been on Earth about 3.5 billion years

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Relative Dating

• Law of Superposition

7
First to Date Rocks

• Arthur Holmes
• Established Radiometric dating

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Absolute Dating

• Determining actual (approximate) age
• Radioactive Dating and Half-life

9
Changes in the Earth

• Short term Earthquakes and volcanic eruptions

10
Long Term Changes

• Mountain building and plate movements.

11
Pangea

• Supercontinent
• Begin to break up about 200 mya

12
Sedimentary Rock in Kansas

• Cretaceous Period
• Once covered by a shallow sea

13
Geologic Time- Explains the presence of
sedimentary rock in Kansas.
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Fossils

• The preserved remains or evidence of _______

15
Extinction

• When all members of a species die out
• ____ of all species have gone extinct

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Mass Extinctions

• Usually marks the end of a time period

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Eras

• Earths history is divided into time segments
  called Eras

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Earths 4 Eras

• Precambrian
• Paleozoic
• Mesozoic
• Cenozoic

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Relative size of each Era
20
Define

• Zoic - animal
• Paleo- ancient
• Meso- middle
• Ceno- recent
• Earths history is divided into eras based on
  ____________

21
Geologic Time Scale

• Used to show when specific types of organisms
  lived on Earth
• The living things on Earth have changed over time

22
Biological Evolution

• The change in living things (genetic make-up)
  over time

23
Two Principles of Evolution

• All species evolved from a previous existing
  species
• All life has a common ancestor

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Artificial Selection

• Wild Mustard

• Dogs evolved from a wolf

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Charles Darwin

• First person to explain how Evolution occurs
• Natural Selection

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Darwins Book

• The Origin of Species by Means of Natural
  Selection

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Natural Selection

• Survival of the Fittest
• The individuals with the best traits are more
  likely to survive and pass on those traits

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DNA

• Shows all living things have a common ancestor
• Also shows how long since common ancestor

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Homologous Structures

• Structures inherited from a common ancestor
• Eg. Hair in mammals

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Homologous Structures

• Bone Structure in vertebrates
• Feathers in birds

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Vestigial Structures

• No apparent function
• Had a function in ancestor

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Vestigial Structures in Humans

• Appendix

• Tail bones

33
Comparative Embryology

• All vertebrate animals have gill slits and
  tails
• The common ancestor of all was a fish

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Whale Evolution
35
Evolution of the Horse
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Life on Earth has Evolved (Changed)

• The species of life now are not the same as the
  ones millions/billions of years ago
• Different types of organisms existed in the
  different Eras

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Early Precambrian

• Atmosphere had very little oxygen

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Mid Precambrian

• The first life forms consisted of prokaryotic
  cells similar to ___.

39
Changes in Precambrian Atmosphere

• Introduction of O2 was caused by the emergence of
  life on Earth.

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Paleozoic Era 540 MYA

• Cambrian Explosion
• The rapid evolution of many different kinds of
  organisms

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Paleozoic Era

• Marine organisms dominate
• Small organisms begin to move to land

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First Fish Evolve 500 MYA
Cambrian Period

• First fish with legs 365 mya (Devonian Period)

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Paleozoic 350 mya
First Amphibians (Devonian Period)
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First Reptiles 310 mya

• Carboniferous Period

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Mesozoic Era 250 mya
First Dinosaurs evolve (Triassic Period)

• Age of the reptiles

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First Mammals Evolve

• From a reptile
• Triassic Period 240 mya

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First Birds 160 mya

• Jurassic Period

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First Primates 100 mya

• Cretaceous Period
• Tree Shrew

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Mesozoic Era Plants

• Conifer plants dominate
• First flowering plants

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Mesozoic Era

• 250 to 65 mya
• Ended when dinosaurs (and many other species)
  went extinct

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Cenozoic

• Modern Era, 65 mya to present
• Age of Mammals

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Mammal Evolution
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Cenozoic Plants

• Flowering plants dominate

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Primate Evolution
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Human Evolution
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Modern Humans

• Evolved in about the last 1 to 200,000 years

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The End