Period 2, Cotter and Emig, History of Earth Timeline

  • (5 BYA) Beginning of the Solar System

    (5 BYA) Beginning of the Solar System
    The solar system was a swirling mass of gas and dust
  • (4.6 BYA) The Earth Grows

    (4.6 BYA) The Earth Grows
    The Earth grew larger as gravity pulled in more debris from collisions.
  • (4 BYA) The Age of the Earth

    (4 BYA) The Age of the Earth
    Scientists examined the surface of the Earth and it's layers to determine it's age.
  • (4 BYA) First Life Forms

    (4 BYA) First Life Forms
    Archaea first populated the Earth.
  • (3.5 BYA) Organisms Use Photosynthesis

    (3.5 BYA) Organisms Use Photosynthesis
    Fossils of stromalites show photosynthetic qualities.
  • (3 BYA) Life Forms Become Photosynthetic

    (3 BYA) Life Forms Become Photosynthetic
    Some forms of life had become photosynthetic.
  • (2.2 BYA) Today's Earth is Formed

    (2.2 BYA) Today's Earth is Formed
    The Earth mostly looked as it does today because the colliding of space debris and emitted gasses from volcanos ceased.
  • (2 BYA) Air Quality

    (2 BYA) Air Quality
    O2 levels reached the level they are at today.
  • (1.5 BYA) Prokaryotes

    (1.5 BYA) Prokaryotes
    A small aerobic prokaryote began to live and reproduce inside a bigger, araerobic prokayote- this is known as endosymbiosis.
  • (1 BYA) Ozone

    (1 BYA) Ozone
    Ozone (O3) formed- protects organisms from harmful UV rays so they could exist on land.
  • (1 BYA) Evolution into Mitochondria

    (1 BYA) Evolution into Mitochondria
    Endosymbiotic aerobic prokaryotes evolved into modern mitochondria, which perform aerobic respiration in eukaryotic cells.
  • (1600-1700) Redi

    (1600-1700) Redi
    Redi's experiment with flies and rotting meat first began to displace the theory of spontaneous generation, but met opposition for "blocking out the vital force", therefore his experiment was looked past by most people.
  • (1700-1800) Spallanzani

    (1700-1800) Spallanzani
    Spallanzani's experiment that used broth and a microscope even further disproved spontaneous generation.
  • (1800-1900) Pasteur

    (1800-1900) Pasteur
    Pasteur won the Paris Academy of Science’s prize to clear up the debate over spontaneous generation. He used broth in curved flasks to allow any vital force in, but to keep bacteria and other things out. The broth stayed clear for 1 year, but only for a day after the curve of the tube was removed.
  • (1900-present) Miller and Urey

    (1900-present) Miller and Urey
    In 1953, Stanley L. Miller and Harold C. Urey tested Oparin’s hypothesis on the condition of the formation of organic molecules on early Earth.
  • (1900-present) Organic Compounds

    (1900-present) Organic Compounds
    In 1970, a newly fallen meteorite led to the finding of a mixture of organic compounds in it.
  • (1900-present) RNA

    (1900-present) RNA
    In 1980, Thomas Cech found that a type of RNA is able to act as a chemical catalyst - a ribosome.
  • (1900-present) Oparin and Haldane

    (1900-present) Oparin and Haldane
    Oparin and Haldane wanted to know how and where elements assembled into organic compounds. They thought that the early atmosphere may have contained ammonia, hydrogen gas, water vapor, and compounds made of hydrogen and carbon, such as methane. They thought that when water cooled, these organic compounds collected in the water, which would then go into different reactions, ending up in essential macromolecules.
  • (1900-present) Fox

    (1900-present) Fox
    Fox did research on the physical structures that may have given rise to the first cells. These structures include microspheres composed of many protein molecules that are organized into coacervates, composed of different types of molecules. They can form spontaneously under certain conditions, different than previously assumed.
  • (1900-present) Simple Organic Compounds

    (1900-present) Simple Organic Compounds
    Since the 1950s there have been scientists attempting to test and revise hypotheses about the origin of simple organic compounds. They have produced amino acids, ATP, and nucelotides.
  • (1900-present)

    New hypotheses on Earth's atmosphere. Some believe it was composed of CO2, N2, and H2O.