1. Early Earth Emily Calder Madeline Cudmore Rebecca Shatney

2. Lacking Evidence…

4. Hadean Era • 10 billion years after formation of the universe. • Earth forms from gas and dust. • Meteors 500 million years uninhabitable. • Hot. • Mass increase temp decrease. • Early atmosphere-CO2, water vapor, nitrogen, methane, ammonia. • Little or no oxygen. • UV rays. • Meteor collisions decrease temp decrease. • Surface hardens. • Water vapor -> rain ->oceans.

5. Beginning of life • 3.85 million years ago. • Greenland. • Need organic chemicals. • RNA. • Underwater geothermal vents.

6. Chronometric Defining • According to events. • Natural disasters, discoveries, dating, life… • Even period divisions. • Random durations. • Neoproterozoic • Ediacaran-630 • Cryogenian-850 • Tonian-1000 • Mesoproterozoic • Stenian-1200 • Ectasian-1400 • Calymmian-1600 • *Million Years Ago

7. Mesoarchean • 3.2- 2.8 billion years ago. • Defined chronometrically. • One of the first supercontinent Vaalbara broke during this time. • Life forms have not changed much.

8. Neorarchean • 2.8 – 2.5 billion years ago. • Also defined chronometrically. • Oxygen photosynthesis first evolved (caused the oxyen catastrophe, which was in the paleoproterzoic era). • The supercontinent Kenorland was formed around 2.7 billion years ago. • Life forms have not changed much.

9. Paleoprotoerzoic Era • Statherian, Orosirian, Rhyacian, Siderian. • 2.5 to 1.6 billion years ago. • Continents first stabilized. • Ur • Arctica • Atlantica • Nena • Columbia • Anaerobic life. • Life using oxygen and photosynthesis appeared. • Oxygen Catastrophe. • Fossil evidence of the first eukaryotes. • Paleontological evidence-1.8 billion years ago- 450 days a year and 20 hours a day.

10. Mesoproterozoic Era • Stenian, Ectasian, Calymmian. • 1.6 to 1.0 billion year ago. • Supercontinent Rodinia. • Great floodplain. • Sexually reproducing life appears. • Multi-cellular animals. • Oxygen levels rise significantly. • No big natural disasters or events. • Continent pieces expand, causing the ocean to shallow.

11. Neoproterozoic Era • Ediacaran, Cryogenian, Tonian. • 1.0 billion to 542 million years ago. • Rapid melting of all ice caps on the world. • Breakup of Rodinia. • Formation of Pannotia. • Rise in carbon dioxide leads to mini ice age. “Snow Ball Earth”. • Rise of soft-bodied multicellular organisms. • Diseases appear. • Corals, sea anemones, hydras, jellyfish, simple metazoa. • Not organs • Just a body cavity or stomach • Mouth, usually surrounded by tentacles.

12. http://www.youtube.com/watch?v=hSdlQ8x7cukhttp://www.youtube.com/watch?v=hSdlQ8x7cukhttp://www.youtube.com/watch?v=hSdlQ8x7cukhttp://www.youtube.com/watch?v=hSdlQ8x7cuk

13. Citations • http://www.mahjoob.com/en/forums/showthread.php?t=275459 • http://lena-panthera.deviantart.com/art/Carte-de-Vaalbara-map-173079888 • http://www.geol.umd.edu/~tholtz/G102/102arch2.htm • http://en.wikipedia.org/wiki/Neoarchean • http://en.wikipedia.org/wiki/Mesoarchean • http://bio1152.nicerweb.com/Locked/media/ch25/clock.html • http://astroclock2010.files.wordpress.com/2010/05/hadean_earth_space_art.jpg • http://www.sciencephoto.com/image/134450/530wm/C0071453-Formation_of_the_Earth,_artwork-SPL.jpg • http://www.fossilmuseum.net/Paleobiology/Images/cyanobacteria.jpg • http://science.nationalgeographic.com/science/prehistoric-world/precambrian • http://en.wikipedia.org/wiki/Paleoproterozoic • http://essayweb.net/geology/timeline/paleoproterozoic.shtml • http://palaeos.com/proterozoic/proterozoic.htm • http://essayweb.net/geology/timeline/mesoproterozoic.shtml • http://www.pbs.org/wgbh/evolution/change/deeptime/precam.html