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(5 BYA) Sun and the Solar System
The sun ignits and the solar system begins to take form -
(4.6 BYA) Molten Earth Forms
(Age of the Earth) Earth began to form by the collision of different space debris. We can determine this by examining the rock layers, strata, and applying Radioactive Dating (using radioactive isotopes to determine the age of the materials). -
(4 BYA) Moon, Earth & Cellular Life Forms
The moon begins to form by collision and the earth its solid crust (some of the oldest rocks found today).The first known cellular life was anaerobic, heterotrophic prokaryotes. Archaea are thought to be very similar to the types of cellular life that first populated the earth. -
(3.5 BYA) Stromatolites
Stromatolites are layered material (added to a tectonic plate of a landmass) formed in shallow water by trapping, binding, and cementation of sedimentary grains by adhering (on the surface of water) of microorganisms. -
(3 BYA) Photosynthesis
Photosynthesis is the process of chemicals that convert CO2 into organic compounds (sugars) using energy from the sun’s light using CO2 and H2O and releases O2 as a waste product. Photosynthesis takes place in plants, algae, many different species of bacteria, but not in archaea. -
(2.2 BYA) Earth Today
Earth appeared much the same as it does today! -
(2 BYA) O2
O2 Levels reach the same level as today. -
(Between 2 BYA-1.5 BYA) Aerobic Prokaryote & Endosymbiosis
Aerobic Prokaryote: organisms the require O2 and have no nucleus or any other membrane-bound organelles.Endosymbiosis: An organism that lives within the body/cells of another organism. -
(1 BYA) O3
Ozone (O3) formed, protecting organisms from harmful UV rays so they could live on land. -
(Between 1600-1700)
Redi’s Experiment: He noticed maggots appeared where adult flies landed. To test why, he placed a piece of meat in an open jar and a piece in a closed jar. There was no maggots in the closed jar, only in the open. -
(Between 1700-1800)
*Spallanzani’s Experiment: He used meat broth and microorganisms to test spontaneous generation by putting the broth in 2 different flasks and covering one then boiled them both. ---> The sealed flask stayed clear and the open flask was cloudy. He said that microorganisms don’t arise spontaneously, but they are carried in the air. *First Microscopes: Scientist began using microscopes to examine tiny organisms. -
(Between 1800-1900)
Pasture’s Experiment: He used a variation of Spallanzani’s experiment to support Spallanzani’s inference by doing the same thing but using flasks with bent necks. Radiometric dating use radioactive isotopes to determine teh age of materials by looking at the half-life of and element (decay). -
(Between 1900-present)
*Urey and Miller: Intended to test Oparin’s hypothesis of the conditions for formation or organic molecules early on Earth. The set-up of the experiment resulted in making a variety of compounds (including 2 amino acids). *Lynn Margulis: Known for her theory on the origin of eukaryotic organelles and her contributions to the endosymobiotic theory (how certain organelles were formed).*Fox: Looked at the physical structures that may have made the first cells by the spontaneous making of differe
