Period 7 Godshall, Weaver, History of Earth Timeline

  • 5 BYA Solar System was Created

    5 BYA Solar System was Created
    The solar system was a swirling mass of gass and dust.
  • 4.6 BYA Earth Grew

    4.6 BYA Earth Grew
    The Earth grew larger due to gravity pulling in more debris. A larger earth would eventually be able to withhold microorganisms and soon humans.
  • 4 BYA Age of Earth

    4 BYA Age of Earth
    The estimated age of Earth is about 700,00 times as long as the period of recorded history.
  • 4 BYA Accumulation of Molecules

    4 BYA Accumulation of Molecules
    Organic molecules began to accumulate such as archae. This was the start of life as we know it,
  • 3.5 BYA

    3.5 BYA
    Lynbgya cells make layered structures called stromatolites. Fossils of Stromatolites were found. These were early cells that would evolve into new organisms.
  • 3 BYA Photosynthesis

    3 BYA Photosynthesis
    Some forms of life adapted to the way of the Earth and become photosynthetic.
  • 2.2 BYA Appearance of Earth

    2.2 BYA Appearance of Earth
    Even though it was billions of years ago the Earth appeared as it does today. This shows that even as life changed the Earth still remained almost the same.
  • 2 BYA Oxygen

    2 BYA Oxygen
    The Earth's oxygen levels reached the levels that are present today. This would be able to support living things on Earth.
  • 1.5 BYA Prokaryotes

    1.5 BYA Prokaryotes
    A type of small prokaryote was engolfed by and began to live and reproduce inside of a longer anaerobic prokaryote-endosmbiosis.
  • 1 BYA Ozone Layer

    1 BYA Ozone Layer
    Ozone (O3) was formed. It protected organisms from harmful UV rays so they could exist and dwell on land.
  • 1600-1700 Spontaneous Generation Questioned

    1600-1700 Spontaneous Generation Questioned
    Redi noticed different developmental methods of flies and people began to question the common belief of spontaneous generation.
  • 1800-1900 Controversy Continues

    1800-1900 Controversy Continues
    Paris Academy of Science offered a prize to whomever could clear up the controversy entirely; Pasteur's experiment won. He found that a flask with a curved neck will not become contaminated, but one without a neck will contaminate within days.
  • 1700-1800 Spallanzani's Experiments

    1700-1800 Spallanzani's Experiments
    Spallanzani wanted to test out the theory of spontaneous generation of microorganisms. He boiled fresh clear broth in two flasks and left one open and the other one closed, The one that was left open became cloudy and the one that was closed remained clear.
  • 1900-present Urey and Miller

    1900-present Urey and Miller
    This grad student and professor set up an experiment to test the hypothesis of Oparin. They set up chambers with the gases that were assumed to be present in the earths atmosphere. When these gases came together they made sparks the symbolized lighting which gave energy for chemical reactions.
  • 1900-Present Oparins Hypothesis

    1900-Present Oparins Hypothesis
    Oparins hypothesis: At high temperatures gases might have formed simple organic compounds.
  • 1900-Present Fox

    1900-Present Fox
    He did research on the physical structures that may have given rise to the first cell.
  • 1900-Present Cech

    1900-Present Cech
    Discovered that a type of RNA is able to act as a chemical catalyst.
  • 1900- Present Margulis

    1900- Present Margulis
    Discovered that early prokaryotic cells might have developed a mutually beneficial relationship.
  • 1900- Present Microscopes

    1900- Present Microscopes
    Early microscopes showed that the world is abundant with tiny creatures. They also showed that microorganisms are simple in construction and are numerous and widespread. Redi used the microscope for his experiments.