Grade 7.2>

Focus Question: When did life begin on Earth and what were extinction cycles?

STS-134 crew patch, International Space Station (ISS)
STS-134 crew patch, International Space Station (ISS)

This page focuses on deep history, the time between the origin of the earth 4.5 to 4.6 billon years ago and the emergence of the first humans 200,000 years ago.

MAP.jpgFor more, see AP World History Key Concept 1.1

The Development of Life on Earth has lecture notes from Professor Rich Townsend, Department of Astronomy, University of Wisconsin--Madison.

Topics on the Page:

Big History
Beginnings of the Solar System
Plate Tectonics and Glaciers
  • Rodinia and Pangaea
Extinction Events
  • Dinosaurs and Extinction
    • Historical Biography page. Mary Anning
      • The De-Extinction Debate

external image Red_apple.jpgA Creation Myths lesson using the concept of Big History (see link 3).

Big History

Screen Shot 2016-08-19 at 1.14.53 PM.png
Infographic from Flowing Data

external image 200px-Paperback_book_black_gal.svg.pngA important resource is the book World History: The Big Eras: A Compact History of Humankind for Teachers and Students (available through the National Center for the Schools. The powerpoint overview just below the essay is also helpful in conceptualizing the time period.
  • The Big History Project (funded by the Bill and Melinda Gates Foundation) is the other place to find current pedagogical ideas on big history. The linked site should have some curriculum materials up by the beginning of the 2011-2012 school year.

Rotating_globe-small.gifGeologic Time Scale from the University of California Museum of Paleontology includes thousands of pages of content on the history of life on earth, with many online, interactive exhibits.

apps.pngBack in Time is an wonderful app that presents the history of the universe and the earth (watch a trailer to see the app in action).

Multimedia.pngEric Idle's Galaxy Song is a fun 2:40 romp through the last several million years. A attention grabbing song for classroom sing alongs.

The Beginnings of the Solar System and the Earth

The path from the start of the universe to the existence of human beings and life on the planet Earth, spans tens of billions of years and unimaginable spaces. Here is a quick look at that complex and varied path.

rotating gif.gifYou can find more information on the beginnings of the solar system at this page.

Expansion of the Universe
Expansion of the Universe

The generally accepted theory on how the universe began is called the Big Bang Theory.

First posited by Georges Lemaitre in 1927, the theory says that all the stuff of the universe is the result of a massive explosion that happened 10 to 20 billion years ago. The theory seeks to explain why the universe is expanding, like ripples in a pool when a rock is dropped in.

Multimedia.pngClick here to look at the planets from different points of view and angles on websites from NASA (links 1, 2).

Multimedia.png The Virtual Fossil Museum shows fossils across geologic time and evolution.

external image 200px-Hebrew_timeline.svg.pngInteractive Pre-Historic Timeline from National Geographic.

See also, History of the Earth in a 24-hour Clock from the website, Flowing Data.

Divisions of Geologic Time is another comprehensive chart of geologic time, from U.S. Geologic Survey

Screen Shot 2016-01-04 at 11.31.08 AM.pngOnce in a Million Years: Teaching Geologic Time is a lesson plan for teaching students the numeracy necessary to comprehend the large numbers used to measure geologic time.

Plate Tectonics and Glaciers

The crust of the earth is divided into dozens of plates of rock which rest on molten magma deep within the earth. These plates "float" on the magma, and often times collide with each other. Plates slip underneath or ride up on top of other plates, causing the continents to drift apart, and creating mountain ranges.
Map Showing Tectonic Plates and Active Volcanoes
Map Showing Tectonic Plates and Active Volcanoes

Along with plate tectonics, glaciers are responsible for the geography of the earth today. Much of North America looks the way that it does because billions of tons of ice once laid on top of it, as far south as New York City. Glaciers are prominent during ice ages, periods of long term reduction in the temperature of the Earth's surface and atmosphere, and have helped shape the history of life on Earth.

Plate Tectonics

Explanation of Plate Tectonics.

Information on Glaciers.


map_icon.jpegRodinia and Pangaea

Rodinia, the First Supercontinent


Multimedia.pngEarth 100 Million Years from Now from YouTube offers a view of how the continents have shifted and will shift over the centuries.

Extinction Events

external image 200px-MassExtinctionTimeline.svg.png

According to Janet Larsen of the Earth Policy Institute, the 5 great extinction events were:
  • 440 million years ago, some 85 percent of marine animal species were wiped out in the earth's first known mass extinction.
    • 367 million years ago, many species of fish and 70 percent of marine invertebrates perished in a major extinction event.
      • 245 million years ago, up to 95 percent of all animalsnearly the entire animal kingdomwere lost in what is thought to be the worst extinction in .
        • 208 million years ago, another mass extinction took a toll primarily on sea creatures, but also some land animals.
          • 65 million years ago, three quarters of all speciesincluding the dinosaurswere eliminated. Ice ages followed. Because of the lack of predators, mammals were able to thrive and the new environment. Eventually, people came on the scene a mere 230,000 years ago.

Link here for an article from MIT on mass extinction. This article refers to new evidence that a buildup of carbon dioxide may have contributed to mass extinction. There also is evidence of wildfires that may have contributed to global warming, and extinction.

Multimedia.pngClick here for a SciShow on Mass Extinctions.

Tyrannosaurus rex.  Image by David Monniaux
Tyrannosaurus rex. Image by David Monniaux

Scenes from The Lost World, 1925
Scenes from The Lost World, 1925

Dinosaurs and Extinction

Impressions from a Lost World, from Pocumtuck Valley Memorial Association explores prehistory findings in New England.

Dinosaurs from the American Museum of Natural History

History Forgot This Rogue Aristocrat Who Discovered Dinosaurs and Died Penniless. Smithsonian Magazine (July 2016)

The Dino Directory, UK Natural History Museum

The De-Extinction Debate

Screen Shot 2017-06-12 at 3.55.03 PM.pngIs It Time for De-Extinction?

Should We Bring Extinct Species Back to Life?


[1] http://space.jpl.nasa.gov/
Look at each planet in our solar system from different points of view and angles; for example, look at the Earth as seen from the moon, or look at Mercury from the Messenger spacecraft—as it would look on today’s date (or, look at the Earth from the Sun on your birthday when you turned ten)!
[2] http://www.jpl.nasa.gov/news/news.cfm?release=2008-018 Look at Saturn as it’s seen from space via the Cassini spacecraft
[3] Quote from David Christian, "What's the Use of Big History?," World History Connected October 2005 <http://www.historycooperative.org/journals/whc/3.1/christian.html> (20 Apr. 2011).
[4] http://www.history.com/news/2012/01/26/native-americans-hailed-from-siberian-highlands-dna-reveals/