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(5 BYA) Solar system begins to form
A cloud of dust and gas was disturbed from a possible nearby Supernova. The explosion caused space waves which squeezed the gas and dust together, forming many smaller planets which collided into one another to form bigger planets. -
(4.6 BYA) Earth begins to Form.
Planet Earth begins to form when the nearby debris, or smaller planets, begin to collide. -
(4 BYA) First Life Forms on Earth
Archae-like organisms are found to be Earth's first life. These organisms were chemosythetic, meaning they obtain energy through chemical reactions. -
(4 BYA) Formation of Earth's Atmosphere
Volcanic activity released the first atmospheric gases on Earth. These elements included Helium and Hydrogen, the lightest gases. Later on Nitrogen and other gases were added -
(3.5 BYA) Origin of Stromatolites
The oldest stromatolites, a type of cyanobacteria, are believed to originate. These organisms obtain energy through photosynthesis, and show signs of the first aerobic respiration. -
(3 BYA) Photosynthetic Life Originates
After the finding of the aerobic Stromatolites 500 million years before, photosynthetic life is commonly found now. These organisms include many forms of Prokaryotic Bacteria. -
(2.2 BYA) Earth Develops
More than two billion years after it began to form, Earth reaches a state similar to what it looks like today. It no longer collided with any smaller planets to grow. -
(2 BYA) Oxygen Levels reached Today's Levels
The composition of Earth's atmosphere is compiled of a nearly identical amount of oxygen compared to that of todays. -
(1.5 BYA) The First Eukaryotes
Small aerobic prokaryotes reproduced inside a larger, anaerobic prokaryote. This is known as endosymbiosis, or the making of the first eukaryotic organism. -
( 1 BYA) Ozone is formed
Ozone formed when oxygen molecules collided with sunlight, which split some oxygen molecules into O, while othrs remained O2. These single and double oxygens then combined to form ozone. Ozone is poisonous to plants and animals, but helpful in controlling UV rays. -
(1665) First Microscopes
The light microscope was used by Robert Hooke to study cell like units inside of cork. These later started the idea of organisms having cells. -
(Mid 1800s) Pasteur's Experiment
Pasteur took Spallanzani's concept and retested it using a curve-neck flask instead of a closed flask. He then took of the neck and found that the broth became cloudy. So, when the flask had a curved neck, no microorganisms could get in. This supported biogenesis. -
(1905) Radiometric Dating
Radiometric dating provided a new way for scientists to find the age of various organic/inorganic objects. It involves using isotopes of various elements to determine the age of the given sample. -
(Early 1900s) Oparin's Hypothesis
Oparin hypothesized how organic compounds may have developed. He thought that at high temperatures, gases may form simple organic compounds like amino acids. -
(Early 1900s) Fox
Studied early cell-like organisms (microspheres and coacervates). This gave us an idea on how the first cells may have evolved -
(1953) Urey and MIller
Experimented using Oparin's hypothesis. They tested various gases being charged with electricity, and they ended up producing organic compounds! -
(1960s) Lynn Margulis
Hypothesized that cellular organelles were a result of endosymbiosis. She found that the organelles were indeed similar to early bacteria. -
(1980s) Thomas Cech
Coined and discovered the term ribozyme. This is a type of RNA that aided in being a catalyst. This produced evidence of self-replicating molecules of RNA. -
(Mid 1700s) Spallanzani's Experiment
Similar to Redi, Spallanzani tested the concept of spontaneous generation on microorganisms. He did this by boiling broth. One flask was covered after being boiled, (to avoid air exposure), while the other flask remained open. It was found that the open flask became cloudy, which meant organisms were inside. He concluded that microorganisms couldn't reproduce in boiled, closed broth. -
(1668) Redi's Experiment
Francesco Redi tested the formation of maggots on rotten meat. He did this by covering one sample so flies couldn't get to it, while leaving another sample out in the open. He found that the covered sample didn't have maggots since the flies couldn't get to it. This supported biogenesis.
