Evolution on Earth

Evolution on Earth

Mr. Reece

Speight Middle School

8th Grade Science

Fossil Record

• The collection of fossils and their placement in order  

• Documents the existence, diversity, extinction, and change of life throughout the Earth’s life history

• Not all types of organisms in the past have left fossils that can be retrieved because of the necessary conditions for fossils

Multiple Choice

Which of the following can be learned by using the fossil record?

• When organisms changed or evolved

• when organisms became extinct

• when organisms appeared on Earth

• All the above

Law of Superposition

• States that in undisturbed rocks layers, the youngest layer is on top and the oldest on bottom

• Many thousands of layers of sedimentary rock provide evidence for the long history of the earth and for the history of changing life forms (fossils)

• More recently deposited rock layers are more likely to contain fossils resembling existing species

Multiple Choice

What are the oldest fossils and why?

• B, C- because they are closest to the top

• A, B- because they are closest to the bottom

• They are all the same age- because they are all found on layer 2

• A, B- because they are found closest to the top

Multiple Choice

Which rock layer formed first?

• W

• Y

• Z

• X

Plate Tectonics Theory

• Movements of continental and oceanic plates caused mountains and deep ocean trenches to form and change the Earth’s crust

• Sea level changes over time have changed continental shelves, created & destroyed inland seas, and shaped land surface

• The evolution of Earth’s living things is linked to the movements of the plates

Plate Tectonics Theory Effects

• Sea level changes as plate tectonics cause the volume of oceans and height of land to change

• The movements of the plates cause changes in climate, and in the types of living things in particular places

Multiple Choice

Which of the following is the name of the ancient supercontinent formed 28 Million Years ago.

• Pangea

• Gondwanda

• Laurasia

• Wakanda

Extinction

• Most species that have lived on the earth are now extinct

• Occurs when the environment changes and the organisms of that species do not have the traits needed to survive and reproduce in the changed environment

• Some organisms from the past are similar to organisms today, but some are quite different

Multiple Choice

Which of these describes a species that has become extinct?

• fewer members of the species are dying than being born

• very few members of a species are alive

• more members of the species are dying than being born

• all members of a species have died

Multiple Choice

When a plant or animal becomes extinct, it is gone _______.

• forever

• until next week

• for 5 years

• to sleep

Multiple Choice

Which is LEAST LIKELY to push a species toward extinction?

• Cutting down entire forest

• Putting animals in a zoo

• Polluting mountain streams

• Introducing new species to an ecosystem with no known natural predator