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(5 BYA) Solar System and Sun was formed.
The solar system was a swirling mass of gas and dust. Over time, most of this material was pulled together by gravity and this formed the sun. -
(4.6 BYA) Earth began to form.
The Earth grew by colliding with space debris. -
(4 BYA) Earth formed
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(4 BYA) Cell first populated Earth
The archaea was the first cell, it was a unicelluar organism that could thrive in extremely harsh environmental conditions. -
(3.5 BYA) Fossils of stromatolites.
Lynbgya, a genus of modern cyanobacteria. the cells often grows in colonies and form layered strictures (stromatolites) -
(3 BYA) Some forms of life become photosynthetic.
(cyanobacteria) -
(2.2 BYA) Earth takes today's shape.
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(2 BYA) O2 levels reached today's levels.
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(2-1.5 BYA) Endosymbiosis Therory
A type of aerobic prokaryotype was engulfed by and began to live and reproduce inside a larger anaerobic prokaryote. -
(1 BYA) Ozone formed
protected organisms from harmful UV rays so they could exist on land. -
(1600-1700) First Microscopes
Robert Hooke was the first to study and record cells by using the early light microscope. People started using microscopes to see tiny creatures (microorganisms). -
(1600-1700) Redi's Experiment
Redi was an Italian scientist. He tested his hypothesis that meat kept away from flies would remain free of maggots. This helped disprove spontanous generation. He put meat in a container and seatled one of them, no flies were on the meat in the sealed one. -
(1800-1900) Pasteur's Experiment
Louis Pasteur was a French scientist. He used a curve-necked flask that allowed air inside but not solid particles. the broth reained clear of a year and then he removed the curved neck and the broth became cloudy. this finally put an end to the idea of spintaneous generation. -
(1900-presemt) Radiometric Dating
A method of establishing the age of materials. -
(1900-present) Oparin's Hypothesis
Alexander I. Oparin (he thought that the early atomophere contained ammonia, hydrogen gas, water vapor, and hyrogen/carbon compounds.) His hypothesis was that at high temperatures, these gases might have formed simple organic compounds (amino acids). -
(1900-present) Urey and Miller
Stanley Miller and Harold Urey set up an experiment using Oparin's hypotheses as a starting point. The experiment used a variety of organic compounds. -
(1900-present) Fox
Sidney Fox did extensive research on the physical structures that may have given rise to the first cells. -
(1900-present) Thomas Cech
Thomas Cech found that a type of RNA found in some unicellular eukaryotes is able to act as a chemical catalyst, similar to the way an enzyme acts. -
(1900-present) Lynn Margulis
She thought that the idea that cellular organelles were originally separate organisms should be reexamined. her research led her to form a theory that shook the foundations of the biological community. -
(1700-1800) Spallanzani's Experiment
Lazzaro Spallanzani was an Italian scientist. He designed an experiment to test the hyothesis of spontanous generation of microorganisms. He believed that microorganisms did not come from the air ("vital force"), but from other microorganisms. He put broth in a flask and boiled it, then sealed one (it remained clear).
