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End of Year Review Geologic Evidence of Change Over Time. 8 th Grade Science Curriculum. Fossil: evidence of past life preserved in rock; Different kinds of fossils are: Petrified fossil: minerals replace all or part of an organism. Change Over Time Geologic Evidence. en.wikivisual.com. - PowerPoint PPT Presentation
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End of Year ReviewGeologic Evidence of Change Over Time
8th Grade Science Curriculum
Change Over TimeGeologic Evidence
Fossil: evidence of past life preserved in rock; Different kinds of fossils are:
1. Petrified fossil: minerals replace all or part of an organism
www.alaska.edu
You can see the rings.
en.wikivisual.com
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
www.ammonoid.com
Cake mold
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.
Mold Cast
esp.cr.usgs.gov
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
Change Over TimeGeologic Evidence
Trace fossil: evidence of activities of ancient organisms; may be tracks, burrows, nest, or trail
Fossil burrow Fossil tracks
igs.indiana.edu
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
Change Over TimeGeologic Evidence
Frozen remains: organisms caught in ice or snow Adult mammoth
flickr.com
Frozen baby mammoth
www.cryptomundo.com
Change Over TimeGeologic Evidence
Fossil record: the complete body of fossils that shows how species and ecosystems change over time
www.rockandwater.com
images.mooseyscountrygarden.com
anthropology.net
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
Change Over TimeGeologic Evidence
Dating Rocks and FossilsRelative 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
ESSENTIAL QUESTION #1
•What is the Law of Superposition?
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
Which can most likely be concluded about the top layer of rock seen in an
undisturbed cliff wall?A. The top layer is older than layers
located farther down the cliff.B. The top layer is younger than layers
located farther down the cliff.C. The top layer contains more fossils
than layers located farther down the cliff.
D. The top layer contains fewer fossils than layers located farther down the
cliff.
Which can most likely be concluded about the top layer of rock seen in an
undisturbed cliff wall?A. The top layer is older than layers
located farther down the cliff.B. The top layer is younger than layers
located farther down the cliff.C. The top layer contains more fossils
than layers located farther down the cliff.
D. The top layer contains fewer fossils than layers located farther down the
cliff.
Change Over TimeRelative Dating
The fossils in layer 3 are “relatively” the same age.
Which layers are older than layer 3?
Which layers are younger than layer 3?
1 and 2
4,5,6,and 7
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.
Based on the Law of Superposition, what can be concluded about
fossils?A. Fossils give clues about the past
climate patterns.B. Fossils form from the hard parts of
organisms.C.The oldest fossils are found in the
lowest rock layers.D.The most recent fossils were
advanced organisms.
Based on the Law of Superposition, what can be concluded about
fossils?A. Fossils give clues about the past
climate patterns.B. Fossils form from the hard parts of
organisms.C.The oldest fossils are found in the
lowest rock layers.D.The most recent fossils were
advanced organisms.
ESSENTIAL QUESTION #2
•How can an unconformity be used as evidence for geologic evolution?
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?
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.
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.
Which does a scientist most likely consider when studying the relative ages of rock layers
in a canyon wall?
A. Chemical weatheringB. Current climate
C.Amount of daily rainfallD.Law of Superposition
Which does a scientist most likely consider when studying the relative ages of rock layers
in a canyon wall?
A. Chemical weatheringB. Current climate
C.Amount of daily rainfallD.Law of Superposition
ESSENTIAL QUESTION #3
•How is the age of the earth determined?
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
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)
www.radiation-scott.org
Daughter isotope: the stable isotope that results from radioactive decay (Helium-3)
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)
www.impcas.ac.cn
Parent isotope
Daughter isotope
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)
Change Over TimeAbsolute Dating
www.kgs.ku.edu
Change Over TimeAbsolute Dating
• All radioactive elements have a specific half-life
library.thinkquest.org
Change Over TimeAbsolute Dating
• After measuring the amount of parent isotopes and daughter isotopes in a rock, scientists use mathematical calculations to determine the rock’s 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.
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
ESSENTIAL QUESTION #3
•How is the age of the earth determined?
•Class discussion.
ESSENTIAL QUESTION #4
•How has the geology of the Earth changed over time?
Continental DriftContinental Drift Theory: theory that states that the gradual shifting of Earth’s plates causes continents to change their global positions over time.
37
38
Plate Tectonics•Correlation: the matching up of rock layers from different locations
•Can use minerals in rock layers or fossils
39
www.answers.com
physics.uwstout.edu
ESSENTIAL QUESTION #4
•How has the geology of the Earth changed over time?
•Class discussion.
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?A.They have similar types of
rocks and fossils.B.They are in the same stage
of succession.C.They exist along the same
line of latitude.D.They have the same climate.
43
Which is the best evidence that two continents were
once connected?A.They have similar types of
rocks and fossils.B.They are in the same stage
of succession.C.They exist along the same
line of latitude.D.They have the same climate.
Plate TectonicsPlate tectonics is the theory that explains how large pieces of the Earth’s outermost layer called tectonic plates move and change shape
44
Plate TectonicsCause of Plate Movements:
Heat from the core sets up convection currents within the mantle. As the mantle moves, it moves the plates above.
45
mediatheek.thinkquest.nl
Plate TectonicsAll Over the World
46cimss.ssec.wisc.edu
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?
ESSENTIAL QUESTION #6
•How have mechanical and chemical weathering impacted the earth?
Weathering
49
Mechanical weathering: is the erosion of rocks and soil caused by wind, water, or ice freezing inside rocks
www.kidsgeo.comwww.flickr.com
soilerosion.net
WIND
WATER
WATER FREEZING
50
Weathering Chemical weathering: is the erosion of rocks and soil caused by chemical reactions
Iron in rock combining with oxygen to form iron oxide (rust)
Pollutants causing acid rain that will react to minerals in natural rock or statues carved from rock
edutel.musenet.org
mail.colonial.net
51
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.
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?A.Asteroid impacts
B.Volcanic eruptionsC.Mechanical and chemical
weatheringD.Continental drift and seafloor
spreading
54
Which process best explains how mountain ranges are
worn down over time?A.Asteroid impacts
B.Volcanic eruptionsC.Mechanical and chemical
weatheringD.Continental drift and seafloor
spreading
ESSENTIAL QUESTION #7
•How have technological processes allowed us to understand change over time?
ESSENTIAL QUESTION #8
•How does remote sensing help scientists make predictions about land use, urban sprawl, and/or resource management ?
Remote Sensing
57
Using satellites to study changes in Earth
58
Remote SensingSatellite pictures/maps can be used to monitor land use, urban sprawl and resource management.
ESSENTIAL QUESTION #8
•Why do scientists use remote sensing when monitoring the Earth?
•Class discussion
ESSENTIAL QUESTION #9
•How does the spectral analysis of reflectance curves help scientists monitor the Earth?
Spectral Analysis
61
The Gulf Stream can be seen (red) in this thermal satellite image
Spectral analysis uses bands of reflected light to monitor changes in the Earth
www.emagazine.com
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 couldn’t be viewed otherwise.
ESSENTIAL QUESTION #10
•How does ground truthing help scientists make predictions about land use, urban sprawl, and/or resource management?
Ground Truthing
64
When scientists study satellite images, they sometimes must go to the areas to see how the image correlates with the actual environment.
www.oakparkjournal.com
ian.umces.edu
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.
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?
ESSENTIAL QUESTION #11
•What evidence is there for climate change?
Global ChangeDue to fossil fuel use and other pollutants, the amount of CO2
has been increasing steadily.
earthobservatory.nasa.gov
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
South Florida is home to millions of people . . .
www.worldwithoutwinter.com
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?
ESSENTIAL QUESTION #11
• What evidence is there for climate change?
• Melting icecaps, sea level rising, slight global temperature increases.
ESSENTIAL QUESTION
• How does remote sensing help scientists make predictions about land use, urban sprawl, and/or resource management ?
• Class discussion
ESSENTIAL QUESTION
•How does the information gathered by these methods help scientists make predictions about change over time?
•Class discussion
ESSENTIAL QUESTION #12
•What does the Geologic Time Scale tell us about
the Earth’s geologic history and the evolution of life?
75
Geologic Time Scale
• The standard method used to divide the Earth’s long natural history into manageable parts
geomaps.wr.usgs.gov
76
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
ESSENTIAL QUESTION #12• What does the Geologic Time Scale tell us
about the Earth’s 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
ESSENTIAL QUESTION #13
•How has the distribution of living things changed over time?
79
Precambrian• Longest time division• 4.6 billion to 544 million. This is equal to a little
more than 4 billion years.Early Earth: Geological ChangesWater condensed and formed oceansStorms dominated the atmosphereAtmosphere was methane, ammonia, and other
chemicalsNo oxygenMoon was closer so appeared larger
80encarta.msn.com
81
PrecambrianConsidered the Age of Algae
Biological 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
82
www.nd.edu
Bacterial Colony
83
Volvox ColonyCells work together to move the entire colony using individual flagella
• 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
io.uwinnipeg.ca
84
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
85
Paleozoic Era• 544 to 245 million years agoGeologic Changes:Life is still found mostly in the oceans but some
moves to the land.Shallow seas cover most of the land including
North AmericaCoral reefs developContinents collide creating the Appalachian
MountainsPangaea forms
86
Paleozoic Era
• As you can see (), most of the East was under water in early Paleozoic
www.paleoportal.org
87
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
88
Paleozoic Era
Pangaea forms
www.canadiangeographic.ca
89
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
Megosaurus www.answers.com
www.50birds.com
90
Which best explains why fossils of the same species of a reptile were discovered in South America and in western Africa?
A. The reptiles evolved in both South America and Africa.
B. The continents of South America and Africa were once joined.
C. Land bridges connected the continents of South America and Africa.
D. The reptiles could swim the distance between South America and Africa.
91
Which best explains why fossils of the same species of a reptile were discovered in South America and in western Africa?
A. The reptiles evolved in both South America and Africa.
B. The continents of South America and Africa were once joined.
C. Land bridges connected the continents of South America and Africa.
D. The reptiles could swim the distance between South America and Africa.
92
Paleozoic EraBiological Changes
• Great “explosion” of new species of invertebrates
www.sciencedaily.com
ESSENTIAL QUESTION #14
•How do index fossils help us understand life forms in the four major geologic eras?
94
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.
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.
96
Paleozoic EraBiological Changes
• First land plants appear
• First spiders and insects appear
www.msu.edu
bleedingeyeballs.com
www.treknature.com
97
Paleozoic EraBiological Changes
• Considered the “Age of Fish” due to the evolution of fish from a worm-like creature to a fish with a jaw
www.life.umd.edu
98
Paleozoic EraBiological Changes
• Simple amphibians then reptiles evolve
animals.howstuffworks.com
ESSENTIAL QUESTION #13
•How has the distribution of living things changed over time?
•Class discussion
100
Mesozoic Era• 245 to 66 million years ago or about 180
million years Geologic Changes:Hot and dry climatePangaea splits into individual continentsWidespread volcanic activity due to the
continents moving
101
Mesozoic EraHot and dry climate
www.3drelax.com
102
Mesozoic EraPangaea splits
www.albury.net.au
103
Mesozoic EraBiological Changes
• Species evolved quickly to take advantage of the land that hadn’t been occupied by many species
• Dinosaurs appear and evolve quickly
www.kittymowmow.com
104
Mesozoic EraBiological Changes
First mammal appears as a small rat-like animal
www.nmnaturalhistory.org
ESSENTIAL QUESTION #15
•What types of catastrophic events have occurred over time?
106
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
107
Which most likely happened to species that are found in the fossil record but have no
living members?
A. They had offspring of a different species.
B. They mutated to other species.
C. They became extinct.D. They never really existed.
108
Which most likely happened to species that are found in the fossil record but have no
living members?
A. They had offspring of a different species.
B. They mutated to other species.
C. They became extinct.D. They never really existed.
109
Cenozoic EraAge of Mammals
66 million years ago to presentGeologic Changes:Rocky Mountains and Himalayas formIce ages periodically cover much of the landLast ice age ends
110
Cenozoic EraContinents
crashing into each other create new mountain ranges like the Himalayas
111
Cenozoic EraPeriodic ice ages create glaciers that reach into most of
North America and other continents
geography.howstuffworks.com
112
Cenozoic EraBiological Changes
Mammals evolve to replace the niches dinosaurs had occupied
exurbanpedestrian.wordpress.com
www.colemangallery.com
dearkitty.blogsome.com
113
Cenozoic EraBiological Changes
First grasses and flowering plants appear for the first time
thoreaugrass.blogspot.com
ruralramblings.com
Ice ages have caused mammals of the Cenozoic Era to adapt to many strange
creatures.
Cenozoic EraBiological Changes
www.joevenusartist.com news.bbc.co.uk/2/hi/science/nature
houseofstaunton.com/.../user-id=/password=
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?
ESSENTIAL QUESTION #16
•How did the geological theories of evolution assist Darwin in his theory of natural selection?
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
Change Over TimeCharles Darwin
• He studied the Galapagos Island wild life and noticed similarities between different species of finches, tortoises, and iguana
photos.mongabay.com
Notice the differences in the shells
Notice the differences in the beaks
www.bbc.co.uk
www.mirrabac.com Iguanas have evolved to eat cactus for one species and sea algae for another
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
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.
ESSENTIAL QUESTION #17
•How are the biological theories of Darwin and Lamark similar and how are they different?
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
Peppered Moth
www.cals.ncsu.edu
Can you see all four moths?
www.arn.org
ESSENTIAL QUESTION ##18
•How does the extinction of a species relate to evolution?
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
Lamark’s ViewsJean-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 giraffe’s neck became longer
because the giraffe would stretch it to reach food
• Although incorrect, his ideas began research into organisms changing over time.
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
Change Over TimeEvolutionArtificial
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
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
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
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
131
Cenozoic EraBiological Changes
First humans appear towards the end of the Cenozoic Era
news.bbc.co.uk