Early Earth
When did Earth form?
4.5 BYA
Life wouldn't be possible without liquid water. Where did Earth's water come from?
Ice crystals in meteors
The Permian Extinction cleared the playing field, allowing ________________ to dominate the world.
Dinosaurs
Around 650 MYA, the ice caps in the north and south poles extend to meet at the equator, beginning a period known as _____________________.
Snowball Earth
Animal life moves onto land.
Meteors carry water crystals to Earth.
Plant life moves onto Land.
Meteors carry water crystals to Earth.
Plant life moves onto Land.
Animal life moves onto land.
What caused the dust/rocks to form early Earth?
Gravity
In addition to carrying water, meteors also brought _____________________, a key ingredient that made early life possible.
Amino acids
Not everything died during Snowball Earth- where did life survive?
In the ocean under the ice.
The Himalayas.
Humans begin walking upright.
Humans first leave Africa.
The rainforests of Africa dry into grasslands.
The rainforests of Africa dry into grasslands.
Humans begin walking upright.
Humans first leave Africa.
Early Earth's spin was ________________ than it is today, and the moon was ________________ to/from the Earth than it is today.
faster; closer
What caused the rainforests of Africa to dry up and turn into grasslands (which led to humans walking on two legs)?
Mountains formed on the west coast of Africa, stopping moisture from the Indian Ocean.
The Permian Extinction was caused by massive volcanic activity, which mostly occurred where?
Modern day Siberia
What was the name of the Mars-sized planet that collided with Earth, eventually forming our moon?
Theia
Permian Extinction.
Meteor wipes out the dinosaurs.
Cambrian Explosion.
Cambrian Explosion.
Permian Extinction.
Meteor wipes out the dinosaurs.
What caused the powerful storms (strong winds) in early Earth?
Its fast rotation
A key to the start of life was chimney-like ______________________, which carried heat and minerals into the ocean from inside the Earth.
hydrothermal vents
Where did the meteor strike 65 mya (which led to the extinction of the dinosaurs)?
Off the coast of Mexico in the Gulf of Mexico.
What happened to allow humans to cross from Asia into North America?
The ice age lowered global sea levels, which exposed a land bridge for them to walk on.
Ozone layer forms.
Photosynthesis begins.
Plants colonize land.
Photosynthesis begins.
Ozone layer forms.
Plants colonize land.
Carbon dioxide, Nitrogen, and Water vapor
Before the Permian Extinction, what allowed animals to grow so big (such as 1 ft long dragonflies or 6 ft long millipedes)?
High oxygen content in the air.
In the Permian Extinction, rising temperatures cause methane trapped in ice to escape, further warming the planet. This causes even more ice to melt and even more methane to escape (and so on...). This process is an example of a ____________________.
Positive Feedback Loop
Earth entered Snowball Earth shortly after a period when lots of new rock formed. What caused the Earth to cool so much?
Cambrian Explosion.
Snowball Earth.
Permian Extinction.
Snowball Earth.
Cambrian Explosion.
Permian Extinction.