Period 4 Veloz, Young, Cunningham. History of Earth Timeline

  • (5 BYA) Sun ignites

    Our solar system was a swirling mass of gas and dust.
  • (4.6BYA) Earth Begins to Form.

    Earth grew larger as gravity pulled in more debris. The collision between earth and space debris also released a great deal of thermal energy.
  • (4BYA) Earth

    Earth still lacks oxygen as solid crust forms.
  • (4BYA) Earth

    First life on Earth.
  • (3.5 BYA) Advancement of Life

    Cells without nucleus's are on earth. Marine photosynthesis starts. Fossils of cells similar to the modern cyonobateria, in the form of stromatolites.
  • (3 BYA)

    Forms of life begin to develop the skill to photosynthesize
  • (2.2 BYA)

    Rapid rise in oxygen; the earth begins to appear as it does today.
  • (2 BYA)

    Eukaryotes began to form.
    O2 (Oxygen) levels reached today’s levels
  • (1.5 BYA)

    Multicelluar organisms begin to grow, respiration develops within mitochondria.
  • 1 BYA

    Ozone (O3) formed – protected organisms from harmful UV rays so they could exist on land. Multicellular life began to form.
  • (1590) First Microscopes

    First Microscopes were invented.
  • (1668) Redi’s experiment

    Redi’s experiment was conducted to prove that life came from other life instead of life coming from non-living objects.
  • (1862) Pasteur’s experiment

    Louis Pasteur’s experiment proved bio-genesis.
  • (1952) Urey and Miller

    Created an experiment to simulate what the early Earth was like to see the chemical origins of life.
  • (1938) Oparin’s hypothesis

    hypothesized that life began in the oceans on early earth about 4 billion years ago. He suggested that first, simple organic molecules containing carbon formed. Energy from the sun, lightning, and earth's heat triggered chemical reactions to produce small organic molecules from substances present in the atmosphere. These molecules were organized by chance into complex organic molecules such as proteins, carbohydrates, and nucleic acids that are essential to life.
  • (1966) Lynn Margulis

    Best known for her theory on the origin of eukaryotic organelles says how eukaryotic cells may have evolved in which they may have developed a mutually beneficial relationship with the prokaryotic cell(s).
  • (1980) Fox

    Contributed by doing extensive research on the physical structures that may have led to the creations of the first cells. Structures include the micro spheres and coarcervates which formed spontaneously in the laboratory from solutions of the simple organic chemicals.
  • (1768) Spallanzani’s experiment

    Spallanzani’s experiment proved that microorganisms can not grow from nothing.
  • (1905) Radiometric dating

    Technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates. It is the principal source of information about the absolute age of rocks and other geological features, including the age of the Earth itself.
  • (1989) Thomas Cech

    Thomas Robert Cech discovered that RNA could cut its own strands of RNA which showed life could have started as RNA.