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(5 BYA) The Beginning
The Solar System was a swirling mass of dust and gas. -
(4.6 BYA) The Sun is Born
Most of the mass began to pull together and form the sun while the remaining debris circled the sun in an orbit. -
(4 BYA) Earthly Collisions
The Earth began to form from colliding debris as gravity pulled in rocks. These collisions released thermal energy and could melt portions of the Earth. Also, radiometric dating usesing half-life and carbon dating can determine how long an object or organism has lived. -
(4 BYA) Archaea
Archaea are unicellular organisms, which thrived under harsh conditions 4 billion years ago. -
(3.5 BYA) Stromatolites
Sromatolites are layered structures of lynbgya cells. There are fossils of stromatolites as old as 3.5 billion years . -
(3 BYA) Progress of Life Forms
Certain forms of life had become photosynthetic. -
(2.2 BYA) Progress of the Earth
The earth looks just aout how it looks today with green grass, lakes and oceans, and rocky terrain. -
(2 BYA) O2 Levels
O2 levels reached today’s levels in the atmosphere. -
(1.5 BYA) Endosymbiosis
A type of small aerobic prokaryote was engulfed by and began to live and reproduce inside of a larger aerobic prokaryote -
(1 BYA) Ozone Creation
Ozone (O3) formed which protected organisms from harmful UV rays so they could exist on land. -
(1600-1700s) Redi's Experiment
He noticed and described the different developmental forms of flies. he observed that tiny worm-like maggots turned into sturdy oval cases, from which flied eventually emerge. he also observed that maggots seemed to appear where adult flies had previously landed -
(1600-1700) First Microscopes
Robert Hooke used a light microscope to look at the cells of a piece of cork. -
(1980's) Cech's Theory
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. He used the term ribozyme for an RNA molecule that an act as a catalyst and promote a specific chemical reaction. Later, Cech’s discovery indicated that ribozymes could act as catalysts for their own replication. -
(1700-1800) Spallanzani's Experiment
Lazzaro Spallanzani designed an experiment to test the hypothesis of spontaneous generation of microorganisms. He hypothesized that microorganisms formed not from air but from other microorganisms. He knew microorganisms grew easily in food, and reasoned that boiling broth in a flask would kill all the microorganisms in the broth, on the inside of the glass, and in the air in the flask. It resulted in clean broth where the flask was bottled and contaminated broth where the flask was open. -
(1800-1900s) Pasteur's Experiment
Louis Pasteur made a curve-necked flask that allowed the air inside the flask to mix with the air outside the flask. This followed Spallanzani's experiment but put the accusation that the heat killed the vital force to shame. -
(1953) Miller-Urey Experiment
Stanley Miller and Harold Urey set up an experiment, using Oparin’s hypothesis as a starting point. A chamber was used to heat up the gases that Oparin mentioned, and used electrical currents to simulate lighting, a source of energy. The result was organisms born from amino-acids that formed in the chambers. -
(1900-present) Fox Research
Sydney Fox has done extensive research on organisms that had been created in a lab with conditions of what the earth might have been like at a certain time. This resulted in membrane-like structures that moved and acted like cells, but where in fact, not alive. -
(1900-present) Margulis Research
Lynn Margulis predicted that Eukaryote cells may have developed a mutual relationship where a smaller aerobic prokaryote would be engulfed, and flourish inside the larger eukaryote, later developing into mitochondria. -
(1920's) Oparin's Experiment
Alexander Oparin and John B.S. Haldane proposed that the atmosphere is made up of ammonia, hydrogen gas, water vapor, and compounds such as methane. Water vapor from the atmosphere formed lakes and rivers and the organisms. formed by high temperatures in the atmosphere from the gases, would have been carried down with the water onto the earth. (Oparin’s Hypothesis).
