Activities

1. Make observations on how the growth of a plant has changed over time.
   
   
2. Make observations on how a certain ecosystem has changed over time.

3. Earlier observations claim water once existed on Mars due to the appearance of canal-like structures. Explain the evidence that exists which makes scientists believe this theory is false.
   
   
4. Describe evidence that supports the theory of evolution.

5. Compare and contrast the theories of continental drift and plate tectonics, including evidence of each theory’s existence.
   
   
6. Develop a logical argument to support which you feel is a more suitable explanation: continental drift or plate tectonics. Infer what the Earth may look like over time is this process continues.

Answer Key/Rubric

1. Acceptable responses must include: reference to a plant, descriptions of how its growth has changed which may include height, size, leaves, fruit/vegetable appearance, etc.
   
   
2. Accept responses may include, but are not limited to: reference to a particular ecosystem, description of its original appearance, description of factors that have changed (such as mention of animals, trees, other plants, water, and inclusion of any manmade objects).
   
   
3. Sample response: In the late 19^th, early 20^th century, a network of long straight lines was observed on Mars’ surface.  Evidence that proved this theory was untrue were that straight lines do not exist in nature, the telescopes were not as clear as more modern telescopes, imaging of its surface proved these indentations were more of an optical illusion.
   
   
4. Acceptable responses may include, but are not limited to:
   Fossil record shows change in early species, many living organisms have similar anatomical structures, geographic similarities of related organisms, genetic changes in organisms over time, and similarities of embryos.
   
   
5. Acceptable responses may include, but are not limited to:
   
   Continental Drift

• The continents were once a large land mass that moved apart over time
• Evidence includes: matching rock layers, continents seem to fit together like a jigsaw puzzle and similar animal and plant fossils were found in places that are not connected (such as Africa and South America)
• Does not explain earth’s landforms and tectonic activities

Plate Tectonics

• Earth’s crust is divided into many plates that move together or apart
• Include the oceanic crust moving (not just the continents)
• Evidence includes: landforms such as mountains, ocean trenches and ridges

Similarities

• Both theories indicate the Earth’s features were not always the same
• Both theories indicate the Earth is constantly moving
• Based on the same idea, though plate tectonics is a more modern theory

6. Acceptable responses must include: Reference to which theory is more suitable, and a prediction of what the Earth may look like in the future.
   Sample response: Plate tectonics is a more suitable theory because it takes into account the change of the ocean floor (which is roughly 70% of the Earth’s surface) not just the exposed continental land.  It explains tectonic activities such as earthquakes and volcanoes, and why there are landforms on the interior of continents and the ocean floor.  I think if this theory continues, mountains will get higher due to plates colliding, and ocean ridges will be higher, and trenches deeper.