Day 3 Extinction cont.ppt

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Day 3 Extinction cont.ppt Powered By Docstoc
					             Warm- Up
• Take out your
  homework.
• Work to be done
  in your notebook
  on page 8.
• Work with table
  partner to
  complete
  Geologic Time
  Scale questions.
Radiometric Dating
 How similar to skittles?




                            2
              Extinction
• An entire species
  disappears
• NATURAL PART OF
  EVOLUTION
• Estimated that 99.9% of all
  species to have ever lived
  have become extinct
• Average survival is 2 to 10
  million years
           Extinction Causes
Extinction Type      How it happens….
Natural Extinction   Climate change, rainfall, volcanic
                     eruption, earthquake, change in
                     geology, predators/ disease

Mass Extinction      Large numbers die out in a short
                     amount of time (50%) Evidence
                     includes abundance of fossils in
                     rock layers
Asteroid Theory      Catastrophic impact with asteroid;
                     thick clouds blocked out sunlight
Gradual Theory       Movement of tectonic plates
                     causes global climate change due
                     to volcanic activity blocking out
                     sunlight
           Us and The “E” Word
• Extinction rate has drastically
  increased
• Many believe this is due to human
  influence
• We have been directly linked to
  habitat destruction, invasion,
  pollution, forest burning, overgrazing,
  overharvesting, climate change,
  poaching, overhunting/fishing



What sorts of species are most
  vulnerable to extinction?
        Review… try not to look!
1.   What is it called when an
     entire species dies out?
2.   What can be dug up from
     Antarctica that allows
     scientists to examine layers
     to give insight into Earth’s
     climate through time?
3.   What Law do undisturbed
     rock layers follow?
Thumbs up T / Thumbs Down F
True or False
4. Radioactive elements are used to
     give an Absolute Age of a fossil.
5. Relative age is an exact numerical
     age for a fossil.
6. Epochs are the largest amounts of
     time on a Geological Time Scale.
7. The Earth is 4.7 Billion years old.
8. Fossils are often found in igneous
     rock.


                                         NO TALKING!
                   Overview
What do scientist believe
  caused the extinction of
  dinosaurs 65 Million years
  ago?
GLOBAL CLIMATE CHANGE
What is the underlying cause
  of all natural species
  extinctions?
ENVIRONMENTAL CHANGE
What percentage of species
  that have ever lived on Earth
  have become extinct?
>99%
     Rock Layers vs. Ice Cores
Which of these shows a record of
  Earth’s climate and climate
  changes over time?
ICE CORES
Which of these BEST shows a
  record of life and evolution on
  Earth?
ROCK LAYERS
How could you explain finding an
  abundance of fossils of a species
  in one particular rock layer?
Extinction event or ICE AGE
               Homework
Assignment:
Begin work on
  Review Sheet for
  test on
  Wednesday!

				
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posted:4/6/2013
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