Transcript Cryolophosaurus ellioti

Geological Evolution
• Plate tectonics or Continental Drift Theory
states…
Earth’s surface is divided into plates that continually
move, taking the continents with them
Types of plate boundaries:
Convergent: plates come
together often forms mountain
chains
Divergent: plates separate
causing faults (earthquake)
Outline of separate tectonic plates
found on Earth
History of Plate
Tectonics
http://pubs.usgs.gov/gip/dynamic/historical.html
Pangaea:
225 MYA- one super continent
Laurasia & Gonwanaland:
200 MYA- Pangaea separated into 2 continents
Today:
7 major continents due to plate movement
Evidence:
Polar Dinosaur
Cryolophosaurus ellioti: fossils found in S. Australia
and in Antarctica
How does this relate to Life Science?
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Climates change as…
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Land moves away from equator
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Land moves toward equator
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Oceans/Seas disappear or appear
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Mountain ranges form
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New coastlines form
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Biomes Change meaning…
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Organisms must adapt to these changes
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Beneficial adaptations will be passed on in successive
generations thus changing the source of genes
(natural selection)
Evolution Clues
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Homologous structures: body structures of different organisms that
are similar in origin and structure
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Forelimbs of chordate animals (animals w/ backbones)
•
http://evolution.berkeley.edu/evolibrary/article/similarity_ms_01
Questions:
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How are tetrapods’ limbs similar?
What is an example of a plant homology?
What is an analogous structure?
Why might some structures evolve independently in various
organisms?
Other Evidence:
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Vestigial Structures: structures that have no known function
•
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In humans: tail bone and muscles around the ear
Similar DNA: organisms of the same species generally share
99 - 99.9% same DNA
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Various Primates of different species all share a common ancestor
Trends in Evolution
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http://evolution.berkeley.edu/evosite/evo101/VIIDTrends.shtml
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How do complex structures like eyes
evolve? http://evolution.berkeley.edu/evosite/evo101/VIICComplexity.shtml
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What is a transitional form?
http://evolution.berkeley.edu/evosite/lines/IAtransitional.shtml
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What is “evolutionary opportunity”?
ex. Dinosaur extinction leads to a rise in mammal species on Earth