VIEWS: 1 PAGES: 10 POSTED ON: 4/6/2013
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!
"Day 3 Extinction cont.ppt"