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(5 BYA) The Solar System Began to Form
Swirling masses of gas and dust was pulled together by gravity and formed the sun. Many planets formed through collision of space debris -
(4.6 BYA) Earth Began to Form
Earth grew by colliding with space debris -
(4 BYA) Earth Grew Larger and Methane was Produced
Earth grew larger as gravity pulled in more debris. Organic molecules (rocks) began to accumulate. Archael species, Methanosacrcina Barkeri, produces methane during metabolism. Cellular life populated Earth similar to archaea. -
(3.5 BYA) Stromatolites
Stromatolites: lynbgya cells grown in colonies and formed layered structures. Fossils or stromatolites are found. -
(3 BYA) Photosynthetic
Some forms of life became photosynthetic. -
(2.2 BYA) Earth
Earth appears as it does today -
(2 BYA) O2 Levels
The O2 levels reach todays levels -
(1.5 BYA) Endosymbiosis
Endosymbiosis: a type of small aerobic prokaryote engulfed by and began to live and reproduce inside of a larger anaerobic prokaryote. -
(1 BYA) 03 Forms
Ozone (O3) formed-protectered organisms from harmful UV rays so they couolcd exist on land -
(1665) Microscopes
Robert Houke discovered the early light microscope in 1665. -
(1668) Francesco Redi: Meat and Flies
Francesco Redi did and experiment to disprove spontaneous gereration. Redi Found that meat that was closed off from flies would not produce maggots, but the meat exposed to flies did. -
(1768) Lazzaro Spallanzani
Lazzaro Spallanzani did and experiment to show that microorganisms would not grow if something was not exposed to the air. In HIs experiment, Spallanzani boiled chhicken broth and put it into two flasks. One was exposed to the air and the other was sealed. Spallanzani's results showed tha th eflask that was exposed to the air became cloudy and the flask sealed off form oxygen was perfectly clear. -
(1905) Radiometric Dating
Radiometric dating is also known as radioactive decay which is when the nuclei of isotopes releases particles or radiant energy until it becomes stable. -
(1920) Oparin's Hypothesis
Oparin's hypothesized that at high temperatures gases in the early atmosphere would form simple organic compounds like amino acids, which ultimately would have resulted in marcromolecules essential to like, like proteins. -
(1930's) Fox
Fox did extensive reseach showing how fist cells may have been created. His research showed that physicla structures, like microsperes and coacertives, may have created the fist cells. Microspheres and coacertives can spontaneously form from solutions of simple organic chemicals in the lab. -
(1960's) Lynn Margulis
Margulis researched how early prokaryotic cells developed a mutually beneficial relationship. She did a lot of research on endosymbiosis which is when a smaller prokaryote is in a larger prokaryotic cell where it starts to live and reproduce -
(1953) Urey and Miller
Urey and Miller did an experiment using oparin's hypothesis. They put the gases in a chamber and had them circulate. They had electric sparks to supply the energy to drive the chemical reactions. This produced a variety of organic compounds including anmino acids. -
(1980's) Thomas Cech
Thomas Cech studied a type of RNAfound in unicelllular eukaryotes whichare able to act as chemical catalysts. This is just like how an enzyme acts. This called this a ribozyme. -
(1861) Louis Pasteur
Louis Pateur diid a follow up experiment on Spallanzani's experiment with chicken broth. This time instead of having one sealed and one exposed flask, he had one flask with boilled chicken broth exposed to oxygen and the other flask was a curve-neck flask with the boiled chicken broth. At the end of his experiment he found that the flask exposed to air was cloudy, but the curve-neck flask had microorganisms in the curve of the flask, but not in the broth which is still clear to this day.
