Journey Through Geologic Time

Approximately how long has life been unfolding on Earth?

• About 400 million years

• About 4 billion years

• About 4 million years

• About 40 billion years

Who published the first laws of stratigraphy in 1669?

• Nicolas Steno

• Giovanni Arduino

• Charles Darwin

• William Smith

What did William Smith use to create a universal time scale?

• Mineral content

• Rock composition

• Soil types

• Fossil comparison

What are the largest increments of the Geologic Time Scale called?

• Periods

• Eras

• Epochs

• Eons

Which Eon is known for having no fossils?

• Phanerozoic

• Proterozoic

• Hadean

• Archean

What significant change occurred during the Archean Eon?

• Emergence of photosynthetic bacteria

• The first ice age

• Appearance of multicellular life

• Formation of the first continents

What was the atmosphere primarily composed of before the appearance of cyanobacteria?

• Hydrogen

• Carbon dioxide

• Nitrogen

• Oxygen

What marks the beginning of the Proterozoic Eon?

• The first ice age

• The appearance of multicellular life

• The rise of oxygen in the atmosphere

• The cooling of Earth's crust

Which organisms were crucial for the oxygenation of the atmosphere?

• Ammonites

• Dinosaurs

• Cyanobacteria

• Eukaryotes

What effect did the rise of oxygen have on early Earth's life forms?

• It caused a mass extinction

• It increased the size of organisms

• It had no significant effect

• It led to the development of land plants