Change Over Time Geologic Evidence

1
End of Year ReviewGeologic Evidence of Change
Over Time
Wake County 8th Grade Science Curriculum
2
Change Over TimeGeologic Evidence

• Fossil evidence of past life preserved in rock
  Different kinds of fossils are
• Petrified fossil minerals replace all or part
  of an organism

en.wikivisual.com
You can see the rings.
www.alaska.edu
3
Change Over TimeGeologic Evidence

• Mold a hollow area in sediment in the shape of
  an organism or part of an organism formed when
  the organism makes an indentation that turns to
  rock over time

Cake mold
www.ammonoid.com
4
Change Over TimeGeologic Evidence

• Cast a solid copy of the shape of an organism
  made by filling in a mold with minerals that
  later turn to rock.

esp.cr.usgs.gov
Mold Cast
5
Change Over TimeGeologic Evidence

• Carbon film an extremely thin coating of carbon
  on rock made when an organism is squeezed by
  rock until only carbon remains

www.geology.ohio-state.edu
6
Change Over TimeGeologic Evidence

• Trace fossil evidence of activities of ancient
  organisms may be tracks, burrows, nest, or trail

igs.indiana.edu
Fossil burrow
Fossil tracks
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Change Over TimeGeologic Evidence

• Amber a hardened resin, or sap, of evergreen
  trees organisms that get trapped in the sticky
  substance becomes part of the rock

pixdaus.com
www.ambermine.com
8
Change Over TimeGeologic Evidence

• Frozen remains organisms caught in ice or
  snow Adult mammoth

Frozen baby mammoth
www.cryptomundo.com
flickr.com
9
Change Over TimeGeologic Evidence

• Fossil record the complete body of fossils that
  shows how species and ecosystems change over time

www.rockandwater.com
anthropology.net
images.mooseyscountrygarden.com
10
Change Over TimeGeologic Evidence

• How do fossils give us the age of organisms that
  lived in the past?

Is this fish fossil a few thousand years old or a
few billion years old?
www.treasure-hunting-team.com
11
Change Over TimeGeologic Evidence

• Dating Rocks and Fossils
• Relative Dating uses information about rock
  layers and the fossil record to determine the age
  relationships between rocks
• Absolute Dating any method of measuring the age
  of an event or object in years

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ESSENTIAL QUESTION 1

• What is the Law of Superposition?

13
Change Over TimeRelative Dating

• Law of Superposition states that the oldest
  rocks lie on the bottom and the youngest rocks
  are on top of any undisturbed sequence of
  sedimentary rocks.

media-2.web.britannica.com
14

• Which can most likely be concluded about the top
  layer of rock seen in an undisturbed cliff wall?
• The top layer is older than layers located
  farther down the cliff.
• The top layer is younger than layers located
  farther down the cliff.
• The top layer contains more fossils than layers
  located farther down the cliff.
• The top layer contains fewer fossils than layers
  located farther down the cliff.

15

• Which can most likely be concluded about the top
  layer of rock seen in an undisturbed cliff wall?
• The top layer is older than layers located
  farther down the cliff.
• The top layer is younger than layers located
  farther down the cliff.
• The top layer contains more fossils than layers
  located farther down the cliff.
• The top layer contains fewer fossils than layers
  located farther down the cliff.

16
Change Over TimeRelative Dating
The fossils in layer 3 are relatively the same
age.
Which layers are older than layer 3?
1 and 2
Which layers are younger than layer 3?
4,5,6,and 7
17
ESSENTIAL QUESTION 1

• What is the Law of Superposition?
• Law of Superposition states that the oldest
  rocks lie on the bottom and the youngest rocks
  are on top of any undisturbed sequence of
  sedimentary rocks.

18

• Based on the Law of Superposition, what can be
  concluded about fossils?
• Fossils give clues about the past climate
  patterns.
• Fossils form from the hard parts of organisms.
• The oldest fossils are found in the lowest rock
  layers.
• The most recent fossils were advanced organisms.

19

• Based on the Law of Superposition, what can be
  concluded about fossils?
• Fossils give clues about the past climate
  patterns.
• Fossils form from the hard parts of organisms.
• The oldest fossils are found in the lowest rock
  layers.
• The most recent fossils were advanced organisms.

20
ESSENTIAL QUESTION 2

• How can an unconformity be used as evidence for
  geologic evolution?

21
Change Over TimeRelative Dating

• Since the top of layer 5 and layer 6 are at the
  same level, are these two layers the same age?
  Why or why not?

22
Change Over TimeRelative Dating

• No, they are not the same age. Layer 5 is older
  than layer 6.
• Unconformity gaps in the rock record created
  when older rock is worn away then new rock is
  layered over it.

You can see that parts of the older layers are
missing.
23
ESSENTIAL QUESTION 2

• How can an unconformity be used as evidence for
  geologic evolution?
• An unconformity can be used to determine relative
  age of rock layers.

24

• Which does a scientist most likely consider when
  studying the relative ages of rock layers in a
  canyon wall?
• Chemical weathering
• Current climate
• Amount of daily rainfall
• Law of Superposition

25

• Which does a scientist most likely consider when
  studying the relative ages of rock layers in a
  canyon wall?
• Chemical weathering
• Current climate
• Amount of daily rainfall
• Law of Superposition

26
ESSENTIAL QUESTION 3

• How is the age of the earth determined?

27
Change Over TimeAbsolute Dating

• When magma or lava hardens, new rock is formed.
• When new rock is formed, some elements isotopes
  are radioactive.

www.kilaueaadventure.com
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Change Over TimeAbsolute Dating

• Isotope an atom that has the same number of
  protons (or the same atomic number) as other
  atoms of the same element do but that has a
  different number of neutrons (thus a different
  atomic mass)
• Parent isotope an atomic nucleus that is
  undergoing decay (Tritium H-3)

Daughter isotope the stable isotope that
results from radioactive decay (Helium-3)
www.radiation-scott.org
29
Change Over TimeAbsolute Dating

• Tritium is radioactive.
• It decays by losing an electron from one of the
  neutrons.
• Radioactive decay the process in which a
  radioactive isotope tends to break down into a
  stable isotope of the same element or another
  element.
• The neutron becomes a proton increasing the
  atomic number from one (Hydrogen) to two (Helium)

Parent isotope
Daughter isotope
www.impcas.ac.cn
30
Change Over TimeAbsolute Dating

• Half-life the time needed for half of a sample
  of radioactive substance to undergo radioactive
  decay (Tritium has a half-life of 12.5 years)

31
Change Over TimeAbsolute Dating
www.kgs.ku.edu
32
Change Over TimeAbsolute Dating

• All radioactive elements have a specific
  half-life

library.thinkquest.org
33
Change Over TimeAbsolute Dating

• After measuring the amount of parent isotopes and
  daughter isotopes in a rock, scientists use
  mathematical calculations to determine the rocks
  age.
• These calculations are based on the half-life of
  the isotopes.
• When the rock is dated, we can know exactly how
  long ago the organism was alive.

34
Change Over TimeAbsolute Dating

• Radioactive Dating the process by which the age
  of a rock is determined by measuring the amount
  of radioactive isotopes present in the rock or
  rock sample

eapbiofield.wikispaces.com
35
ESSENTIAL QUESTION 3

• How is the age of the earth determined?
• Radioactive dating of Earth and moon rocks (4.6
  billion years old).

36
ESSENTIAL QUESTION 4

• How has the geology of the Earth changed over
  time?

37
Continental Drift
Continental Drift Theory theory that states
that the gradual shifting of Earths plates
causes continents to change their global
positions over time.
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(No Transcript)
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Plate Tectonics

• Correlation the matching up of rock layers from
  different locations
• Can use minerals in rock layers or fossils

physics.uwstout.edu
www.answers.com
40
ESSENTIAL QUESTION 4

• How has the geology of the Earth changed over
  time?
• Continents have moved because of the plates.

41
ESSENTIAL QUESTION 5

• How has the Earth been impacted by major
  geological events?

42

• Which is the best evidence that two continents
  were once connected?
• They have similar types of rocks and fossils.
• They are in the same stage of succession.
• They exist along the same line of latitude.
• They have the same climate.

43

• Which is the best evidence that two continents
  were once connected?
• They have similar types of rocks and fossils.
• They are in the same stage of succession.
• They exist along the same line of latitude.
• They have the same climate.

44
Plate Tectonics
Plate tectonics is the theory that explains how
large pieces of the Earths outermost layer
called tectonic plates move and change shape
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Plate Tectonics
Cause of Plate Movements
Heat from the core sets up convection currents
within the mantle. As the mantle moves, it moves
the plates above.
mediatheek.thinkquest.nl
46
Plate TectonicsAll Over the World
cimss.ssec.wisc.edu
47
ESSENTIAL QUESTION 5

• How has the Earth been impacted by major
  geological events?
• Plate tectonics has caused continents to move to
  different climates.
• Movement of plates cause mountains to build,
  earthquakes, and volcanoes.
• What other major geological events can you think
  of?

48
ESSENTIAL QUESTION 6

• How have mechanical and chemical weathering
  impacted the earth?

49
Weathering
Mechanical weathering is the erosion of rocks
and soil caused by wind, water, or ice freezing
inside rocks
WATER ?
soilerosion.net
www.kidsgeo.com
www.flickr.com
WATER FREEZING ?
WIND ?
50
Weathering
Chemical weathering is the erosion of rocks and
soil caused by chemical reactions
mail.colonial.net
edutel.musenet.org
Pollutants causing acid rain that will react to
minerals in natural rock or statues carved from
rock
Iron in rock combining with oxygen to form iron
oxide (rust)
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Weathering

• Mountains formed by plate tectonics are
  constantly being worn down by mechanical and
  chemical weathering.
• The Himalayas are the largest mountains on Earth.
• The Appalachian Mountains used to be as large as
  the Himalayas.
• The Appalachians are now just the worn remnants
  of a once immense mountain range.

52
ESSENTIAL QUESTION 6

• How have mechanical and chemical weathering
  impacted the earth?
• Mountains and other land features are worn down.

53

• Which process best explains how mountain ranges
  are worn down over time?
• Asteroid impacts
• Volcanic eruptions
• Mechanical and chemical weathering
• Continental drift and seafloor spreading

54

• Which process best explains how mountain ranges
  are worn down over time?
• Asteroid impacts
• Volcanic eruptions
• Mechanical and chemical weathering
• Continental drift and seafloor spreading

55
ESSENTIAL QUESTION 7

• How have technological processes allowed us to
  understand change over time?

56
ESSENTIAL QUESTION 8

• How does remote sensing help scientists make
  predictions about land use, urban sprawl, and/or
  resource management ?

57
Remote Sensing
Using satellites to study changes in Earth
58
Remote Sensing
Satellite pictures/maps can be used to monitor
land use, urban sprawl and resource management.
59
ESSENTIAL QUESTION 8

• Why do scientists use remote sensing when
  monitoring the Earth?
• To see the change of Earths surface over time

60
ESSENTIAL QUESTION 9

• How does the spectral analysis of reflectance
  curves help scientists monitor the Earth?

61
Spectral Analysis
The Gulf Stream can be seen (red) in this thermal
satellite image
www.emagazine.com
Spectral analysis uses bands of reflected light
to monitor changes in the Earth
62
ESSENTIAL QUESTION 9

• How does the spectral analysis of reflectance
  curves help scientists monitor the Earth?
• It aids scientists by helping them get a visual
  picture of the atmosphere and surface that
  couldnt be viewed otherwise.

63
ESSENTIAL QUESTION 10

• How does ground truthing help scientists make
  predictions about land use, urban sprawl, and/or
  resource management?

64
Ground Truthing
When scientists study satellite images, they
sometimes must go to the areas to see how the
image correlates with the actual environment.
ian.umces.edu
www.oakparkjournal.com
65
ESSENTIAL QUESTION 10

• How does ground truthing help scientists make
  predictions about land use, urban sprawl, and/or
  resource management?
• This process lets them observe up close, what
  satellites have shown them.

66
ESSENTIAL QUESTION 7

• How have technological processes allowed us to
  understand change over time?
• Satellite imagery has made it easier to observe
  plate tectonics.
• Machines can dig deeper to study rock layers.
• Can you think of others?

67
ESSENTIAL QUESTION 11

• What evidence is there for climate change?

68
Global Change

• Due to fossil fuel use and other pollutants, the
  amount of CO2 has been increasing steadily.

earthobservatory.nasa.gov
69
Global Change

• Even though we have not experienced huge
  increases in temperatures, evidence of global
  warming is the melting of the polar ice caps.

globalwarmingsiren.com
70
  South Florida is home to millions of people . .
.

• This is what Florida would look like if all ice
  on this planet melted.
• What would happen to the temperature if all ice
  on the planet were gone?

www.worldwithoutwinter.com
71
ESSENTIAL QUESTION 11

• What evidence is there for climate change?
• Melting icecaps, sea level rising, slight global
  temperature increases.

72
ESSENTIAL QUESTION 12

• What does the Geologic Time Scale tell us about
  the Earths geologic history and the evolution of
  life?

73
Geologic Time Scale

• The standard method used to divide the Earths
  long natural history into manageable parts

geomaps.wr.usgs.gov
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Geologic Time Scale

• Eon largest division of geologic time
• Era A unit of geologic time that includes two
  or more periods
• Period a subdivision of the eras in geologic
  time
• Epoch A subdivision of a geologic period
• Divisions are determined by the major life forms
  of the time

75
ESSENTIAL QUESTION 12

• What does the Geologic Time Scale tell us about
  the Earths geologic history and the evolution of
  life?
• The four eras of the geologic time scale were set
  up based on the life of the era.
• Precambrian Bacteria and small multi-celled
  organisms
• Paleozoic Fish and arthropods
• Mesozoic Reptiles
• Cenozoic Mammals

76
ESSENTIAL QUESTION 13

• How has the distribution of living things changed
  over time?

77
Precambrian

• Longest time division
• 4.6 billion to 544 million. This is equal to a
  little more than 4 billion years.
• Early Earth Geological Changes
• Water condensed and formed oceans
• Storms dominated the atmosphere
• Atmosphere was methane, ammonia, and other
  chemicals
• No oxygen
• Moon was closer so appeared larger

78
encarta.msn.com
79
PrecambrianConsidered the Age of
AlgaeBiological Changes

• Simple single celled bacteria evolve in the
  oceans.
• Some bacteria adapt to photosynthesize and evolve
  into algae
• The atmosphere began to build up oxygen
• Some bacteria adapt to use oxygen in respiration
• Some cells form simple colonies
• Colonies of cells begin to evolve into small
  invertebrates

80
Bacterial Colony
www.nd.edu
81
Volvox ColonyCells work together to move the
entire colony using individual flagella
io.uwinnipeg.ca

• Individual cells are connected like a primitive
  life form
• Small colonies form inside and become individual
  colonies when the large one dies and breaks open

www.morning-earth.org
82
End of the Precambrian

• Oxygen in the atmosphere
• Most life is single celled organisms
• All life exists in oceans

These are stromatolites formed by build-up of
blue-green algae
83
Paleozoic Era

• 544 to 245 million years ago
• Geologic Changes
• Life is still found mostly in the oceans but some
  moves to the land.
• Shallow seas cover most of the land including
  North America
• Coral reefs develop
• Continents collide creating the Appalachian
  Mountains
• Pangaea forms

84
Paleozoic Era
www.paleoportal.org

• As you can see (?), most of the East was under
  water in early Paleozoic

• ?

85
Paleozoic Era

• Continents collide causing the Appalachian
  Mountains to form
• This causes sea shell fossils to be on the top
  of mountains

www.paleoportal.org
?
86
Paleozoic Era
Pangaea forms
www.canadiangeographic.ca
87
Paleozoic Era

• Mesosaurus was a species that lived on Pangaea.
• Fossils of the reptile and other species were
  made.
• When Pangaea broke up, the fossils could still be
  found on the different continents proving they
  were once connected

www.50birds.com
Megosaurus
www.answers.com
88

• Which best explains why fossils of the same
  species of a reptile were discovered in South
  America and in western Africa?
• The reptiles evolved in both South America and
  Africa.
• The continents of South America and Africa were
  once joined.
• Land bridges connected the continents of South
  America and Africa.
• The reptiles could swim the distance between
  South America and Africa.

89

• Which best explains why fossils of the same
  species of a reptile were discovered in South
  America and in western Africa?
• The reptiles evolved in both South America and
  Africa.
• The continents of South America and Africa were
  once joined.
• Land bridges connected the continents of South
  America and Africa.
• The reptiles could swim the distance between
  South America and Africa.

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Paleozoic EraBiological Changes

• Great explosion of new species of invertebrates

www.sciencedaily.com
91
ESSENTIAL QUESTION 14

• How do index fossils help us understand life
  forms in the four major geologic eras?

92
Paleozoic EraBiological Changes

• Trilobites appear at the beginning of this era
• then disappear at the end making them an index
  fossil for the Paleozoic Era
• Index fossil is found in a narrow time range but
  widely distributed around the earth used to
  date rock layers in any era.

93
ESSENTIAL QUESTION 14

• How do index fossils help us understand life
  forms in the four major geologic eras?
• Index fossils, if found in a rock layer with
  other fossils, can help us determine the relative
  age of that layer and the other fossils in it.

94
Paleozoic EraBiological Changes

• First land plants appear
• First spiders and insects appear

www.msu.edu
www.treknature.com
bleedingeyeballs.com
95
Paleozoic EraBiological Changes
www.life.umd.edu

• Considered the Age of Fish due to the evolution
  of fish from a worm-like creature to a fish with
  a jaw

96
Paleozoic EraBiological Changes

• Simple amphibians then reptiles evolve

animals.howstuffworks.com
97
ESSENTIAL QUESTION 13

• How has the distribution of living things changed
  over time?
• Evolved from simple, single-celled organisms to
  more complex organism (amphibians to reptiles)

98
Mesozoic Era

• 245 to 66 million years ago or about 180 million
  years
• Geologic Changes
• Hot and dry climate
• Pangaea splits into individual continents
• Widespread volcanic activity due to the
  continents moving

99
Mesozoic Era

• Hot and dry climate

www.3drelax.com
100
Mesozoic Era

• Pangaea splits

www.albury.net.au
101
Mesozoic EraBiological Changes

• Species evolved quickly to take advantage of the
  land that hadnt been occupied by many species
• Dinosaurs appear and evolve quickly

www.kittymowmow.com
102
Mesozoic EraBiological Changes
First mammal appears as a small rat-like animal
www.nmnaturalhistory.org
103
ESSENTIAL QUESTION 15

• What types of catastrophic events have occurred
  over time?

104
Mesozoic EraBiological Changes

• End of the Mesozoic Era ends with the sudden
  extinction of all dinosaurs
• One theory is that a comet hit the earth causing
  a cloud to cover the earth for years

105

• Which most likely happened to species that are
  found in the fossil record but have no living
  members?
• They had offspring of a different species.
• They mutated to other species.
• They became extinct.
• They never really existed.

106

• Which most likely happened to species that are
  found in the fossil record but have no living
  members?
• They had offspring of a different species.
• They mutated to other species.
• They became extinct.
• They never really existed.

107
Cenozoic EraAge of Mammals

• 66 million years ago to present
• Geologic Changes
• Rocky Mountains and Himalayas form
• Ice ages periodically cover much of the land
• Last ice age ends

108
Cenozoic Era

• Continents crashing into each other create new
  mountain ranges like the Himalayas

109
Cenozoic Era

• Periodic ice ages create glaciers that reach into
  most of North America and other continents

geography.howstuffworks.com
110
Cenozoic EraBiological Changes
exurbanpedestrian.wordpress.com
dearkitty.blogsome.com
www.colemangallery.com

• Mammals evolve to replace the niches dinosaurs
  had occupied

111
Cenozoic EraBiological Changes

• First grasses and flowering plants appear for the
  first time

ruralramblings.com
thoreaugrass.blogspot.com
112
Cenozoic EraBiological Changes

• Ice ages have caused mammals of the Cenozoic Era
  to adapt to many strange creatures.

news.bbc.co.uk/2/hi/science/nature
www.joevenusartist.com
houseofstaunton.com/.../user-id/password
113
ESSENTIAL QUESTION 15

• What types of catastrophic events have occurred
  over time?
• Comets and meteors have struck the planet causing
  global change.
• Many ice ages have occurred causing specie
  extinctions.
• Can you thing of others?

114
ESSENTIAL QUESTION 16

• How did the geological theories of evolution
  assist Darwin in his theory of natural selection?

115
Change Over TimeCharles Darwin

• At the age of 21, Darwin sailed on board the HMS
  Beagle as science officer

richarddawkins.net
www.genghisthedog.com
Voyage of the HMS Beagle
116
Change Over TimeCharles Darwin

• He studied the Galapagos Island wild life and
  noticed similarities between different species of
  finches, tortoises, and iguana

www.mirrabac.com
Iguanas have evolved to eat cactus for one
species and sea algae for another
Notice the differences in the shells
photos.mongabay.com
Notice the differences in the beaks
www.bbc.co.uk
117
Change Over TimeCharles Darwin

• Based on these similarities, Darwin came to the
  conclusion that species evolved over time to
  adapt to different environments
• He called this adaptation natural selection or
  survival of the fittest

www.thisviewoflife.org
118
ESSENTIAL QUESTION 16

• How did the geological theories of evolution
  assist Darwin in his theory of natural selection?
• He studied the different islands of the Galapagos
• He found that the islands had different climates
  and food sources therefore the animals had
  adapted to fit those environments.
• He also found that fossils in different parts of
  the world supported his theory.

119
ESSENTIAL QUESTION 17

• How are the biological theories of Darwin and
  Lamark similar and how are they different?

120
Change Over TimeEvolution

• Theory an explanation that ties together many
  hypothesis and observations
• Adaptation a trait that increases the chances
  that an organism will survive and reproduce

Can you see all four moths?
www.cals.ncsu.edu
Peppered Moth
www.arn.org
121
ESSENTIAL QUESTION 18

• How does the extinction of a species relate to
  evolution?

122
Change Over TimeEvolution

• Natural Selection survival of the fittest
  organisms that are the best adapted to their
  environment and the ones that will live long
  enough to reproduce and pass on their favorable
  adaptations

123
Lamarks Views

• Jean-Baptiste Lamarck
• 1 August 1744 18 December 1829
• Contributed his evolution theory before Darwin
• His theory included the idea that organisms
  developed traits because they needed them
• Example A giraffes neck became longer because
  the giraffe would stretch it to reach food
• Although incorrect, his ideas began research into
  organisms changing over time.

124
ESSENTIAL QUESTION 17

• How are the biological theories of Darwin and
  Lamark similar and how are they different?
• Both thought organisms had changed over time.
• Darwin supported natural selection.
• Lamark thought that organisms changed due to
  environmental stresses on them

125
Change Over TimeEvolution

• Artificial Selection
• the breeding of plants and animals with desired
  traits to attempt to produce offspring with these
  same traits
• all domesticated animals and plants were
  developed using this process
• also known as selective breeding

www.harunyahya.com
126
Change Over TimeEvolution

• Speciation the process of natural selection
  producing a new species out of existing species
  over thousands or millions of years
• Species a group of organisms that can breed and
  produce fertile offspring most specific
  classification of living things
• Extinction The evolutionary termination of a
  species caused by the failure to reproduce and
  the death of all remaining members of the
  species the natural failure to adapt to
  environmental change

127
Change Over TimeEvolution

• Evolution the change in population of a species
  over time caused by differences in variation or
  successful mutations that allow individuals to
  survive and pass on their genes
• Mutation a random change to a gene that results
  in a new trait
• Biological Evolution the change over time of
  living organisms

128
ESSENTIAL QUESTION 18

• How does the extinction of a species relate to
  evolution?
• If a species becomes extinct, they were not able
  to adapt to the changing environment.
• Only those able to adapt (change) will survive

129
Cenozoic EraBiological Changes

• First humans appear towards the end of the
  Cenozoic Era

news.bbc.co.uk