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5 Billion Years Ago...
Swirling mass of gas. Materials were pulled together by the gravity and formed the sun. Planets formed after a series of collisions. -
4.6 Billion Years Ago...
Earth grew larger as gravity pulled in more debris. -
4 Billion Years Ago...
Collisions between Earth and Space debris, also released thermal energy. Almost all cells were heterophs. -
3.5 Billion Years Ago...
Fossils of stromatolites are formed. -
3 Billion Years Ago...
Photosynthesis and respiration occured. Forms of life became photosynthesis. -
2.2 Billion Years Ago...
Earth appeared as much as it does today. -
2 Billion Year Ago...
Oxygen levels reached today's levels -
2 Billion Years Ago - 1.5 Billion Years Ago...
Small aerobic prokaryotic was engulfed and began to live and reproduce inside of a larger anerobic prokaryotic called endosymbiosis. -
1 Billion Years Ago...
Ozone formed - protected organisms from harmful UV rays so they could exist on land. -
1600-1700
Redi (1627-1697) Redi conducted an experiment in 1668 to test a hypothoseis. That if meat was kept away from flies, that maggots did not grow in/on meat. Microscope: Revealed that the world had a bunch of tiny organisims living around us. -
1700-1800
Spallanzani's Experiement: Designed an experiement to test the hypothesis of spontaneous generation of micro-organisims. Although he had solid data, his experiement was ahead of his time. -
1800-1900
Pasteur's Experiement: To test his experiment he uses broth. He proved that contamenation was due to microrganisims in air soiling the broth, not the "divine power." -
1900-Present
Radioactive Dating: The atomic number of an element is the number of protons in the nucleus. Oparin's Hypothesis: Specific gases might have formed simple organic compounds. Urey & Miller: Produced a lot of organic compunds. Cech: Found thata type of RNA found in some unicellular eukaryotes is able to act as a catalyst, similar to enzymes, this is known as endosymbosis. Lynn Margulis: Proposed that a prokaryotic cells may have devoleped a mutually benefecial relationship.
