Earth's History and Evolution

Mass Extinction (K-T Extinction)

At the end of the Mesozoic Era, dinosaurs and 70% of all life vanished, possibly due to an asteroid collision

Carbon Dioxide

Volcanic activity added carbon dioxide to the early atmosphere

Water Cycle

Water vapor condensed and precipitated on the Earth's surface

Amphibians

Amphibians followed plants and arthropods in colonizing dry land

Mass Extinction (Holocene Extinction)

Another mass extinction occurred with the close of the last ice age, possibly due to climate change and species competition

Photosynthesis

Archeobacteria used CO2 for photosynthesis and released molecular oxygen into the atmosphere

Water Vapor

Clouds of water vapor combined with carbon dioxide in the early atmosphere

Methane, Ammonia, Hydrogen, Water Vapor

Compounds in the atmosphere precipitated into the ocean and were the basis for the building blocks of life

Volcanic Activity

Continued volcanic activity shaped the surface of the Earth

Dinosaurs

Dinosaurs ruled the Earth during the Mesozoic Era

Carboniferous Period

During the Carboniferous period, much of the Earth's land was in tropical locations and photosynthesis was at an all-time high

Formation of Earth

Earth formed from heated, coalescing dust and gases

Early Atmosphere

Earth's early atmosphere started as mostly hydrogen and helium

Glaciers

Glaciers have advanced and retreated numerous times over the last 60 million years

Ozone Production

Molecular oxygen combined with atomic oxygen to produce ozone, a natural UV screen

Fossil Fuels

Incompletely decomposed vegetation from the Carboniferous period formed modern fossil fuel reserves

Colonization of Dry Land

Living organisms could exploit the exposed rocks on dry land

Mammal-Like Reptiles

Mammal-like reptiles appeared during the Paleozoic Era

Multi-Cellular Life

Multi-cellular life forms arose 1.5 billion years ago

Plants and Arthropods

Plants and arthropods were the first organisms to colonize dry land

Miller & Urey Experiment

Stanley Miller and Harold Urey recreated conditions of the primitive Earth and produced organic molecules

Cambrian Explosion

The Burgess Shale reveals a burst of new life forms during the Cambrian period

Cenozoic Era

The Cenozoic Era is known as the 'Age of Mammals'

Oceans

The Earth cooled as the oceans filled from precipitating water vapor

Mesozoic Era

The Mesozoic Era was characterized by deserts and the dominance of dinosaurs

Birds

The extinction of dinosaurs gave way to the rise of birds

Single-Celled Organisms

The first single-celled organisms evolved in the water and were protected from UV rays

Mass Extinction

The greatest mass extinction occurred at the end of the Paleozoic Era, causing the disappearance of 90% of all life forms

Hyperoxic Atmosphere

The hyperoxic atmosphere during the Carboniferous period may have contributed to the enormous growth of insects

Ozone Layer

The ozone layer protects life on Earth and has been damaged by human use of CFCs

Solar Radiation

The thin atmosphere allowed solar radiation to reach the Earth's surface