Period 7, Shank & Switch, History of Earth Timeline

  • (5 BYA)-Solar system was created

    (5 BYA)-Solar system was created
    It was a swirling mass of gas and dust. It affected our lives.
  • (4.6 BYA)-Earth formed

    (4.6 BYA)-Earth formed
    Earth formed by colliding with space debris. It affected our planet.
  • (4 BYA)-Age of Earth

    (4 BYA)-Age of Earth
    Volcanoes emitted gas forming an atmosphere. It is the estimated age of Earth as well. It affects us because without the atmosphere there would be no life at all.
  • (4 BYA)-Archaea was the first cellular life that populated Earth

    (4 BYA)-Archaea was the first cellular life that populated Earth
    Archaea was thought to be similar to the types of cellular life that first populated Earth. Archaea lets us explore the different forms of life.
  • (1 BYA)-Ozone formed

    (1 BYA)-Ozone formed
    The ozone layer protected organisms from harmful UV rays so they could exist on land.
  • (3.5 BYA)-Fossils are found

    (3.5 BYA)-Fossils are found
    Fossils of stromatolites are known. It's important so that we know that life existed before us.
  • (3 BYA)-Life was becoming photosynthetic

    (3 BYA)-Life was becoming photosynthetic
    Some, not all, forms of life had become photosynthetic. Without photosynthesis, us humans would not be able to live and breathe.
  • (2.2 BYA)-modern Earth

    (2.2 BYA)-modern Earth
    Earth probably appeared much as it does today. It affects us because it is the environment that we are living in today.
  • (2 BYA)-Oxygen levels reached today's levels

    (2 BYA)-Oxygen levels reached today's levels
    It's important because without oxygen we wouldn't be able to breathe.
  • (Between 2 BYA-1.5 BYA)-Anaerobic prokaryote was found

    (Between 2 BYA-1.5 BYA)-Anaerobic prokaryote was found
    Anaerobic prokaryote was found, which is the endosymbiosis theory. This stage is reproduction beginning.
  • (1665)-First Microscope was created

    (1665)-First Microscope was created
    Robert Hooke studied nature by using a light microscope. A light microscope is an instrument that uses optical lenses to magnify objects by bending light rays. Beginning in the 17th century, naturalists used microscopes to study small objects unable to be seen by the naked eye.
  • (1668)-Redi's experiment

    (1668)-Redi's experiment
    Francesco Redi created an experiment. In this experiment, maggots were found only in the control jars because that was the only place where adult flies could reach the meat to lay eggs.
  • (1700s)-Spallanzani's experiment

    (1700s)-Spallanzani's experiment
    In Spallanzani's experiment, he wanted to try boiled broth. This is what he did: he boiled the meat broth in open flasks. Then he sealed the flasks of the experimental group by melting the glass necks of the flasks closed. The broth inside remained uncontaminated by microorganisms.
  • (mid-1800s)-Pasteur's experiment

    (mid-1800s)-Pasteur's experiment
    In Pasteur's experiment, a flask with a curved but still open neck prevented microorganisms from entering. Broth boiled in the flasks became contaminated by microorganisms only when the curved necks were removed from the flasks.
  • (1920s)-Oparin's Hypothesis

    (1920s)-Oparin's Hypothesis
    Oparin thought that the early atmostphere contained ammonia. Eventually, he thought that gases resulted in macromolecules essential to life, like proteins. This is important because without this hypothesis we would be living in an atmosphere with ammonia.
  • (1949)-Radiometric Dating

    (1949)-Radiometric Dating
    Radiometric dating is the process in which there are methods for establishing the age of materials. This is important because this helps us know when materials were created.
  • (1953)-Urey and Miller

    (1953)-Urey and Miller
    Their experiment was intended to test Oparin's hypothesis about the conditions for the formation of organic molecules on the early Earth. This was an important milestone in the science field.
  • (1950s-1960s)-Fox researched structures of first cell

    (1950s-1960s)-Fox researched structures of first cell
    Sidney Fox researched on the physical structures that may have given rise to the first cell. It's importance is that it allows us to explore human and animal life.
  • (1966)-Lynn Margulis

    (1966)-Lynn Margulis
    Lynn proposed the theory of endosymbiosis, which are large prokaryotic unicellular organisms engulfed in smaller prokaryotic, unicellular organisms. The prokaryotes evenutally grow but they also carry their own DNA. It's important because these cells usually perform respiration.
  • (Early 1980s)-Thomas Cech found the ribozyme

    (Early 1980s)-Thomas Cech found the ribozyme
    Cech found that a type of RNA found in some unicellular eukaryotes are able to act as a chemical catalyst, which is similar to the way an enzyme acts. He called it a ribozyme. This means for an RNA molecule that can act as a catalyst and to promote a specific chemical reaction. It's important because he discovered the roles of RNA.