-
5 Billion Years Ago
Solar system was a swirling mass of gas and dust. Over time, this was was pulled together by gravity and made the sun. Planets began to form from collision of space debris. -
4.6 Billion Years Ago
The earth began to form as gravity pulled in more debris. The earth sat, also, in a vital area of the solar system. Although just a floating mass of debris Earth had a lot of potential for the future from the start. -
4 Billion Years Ago
Bacteria first populated earth. Methanosarcina barkeri is and archae speciees that produces methane during metabolism. Bacteria was important because it proves to be the first form of life on Earth. -
4 Billion Years Ago
Layers of sedimintary rocks began to form. Sedimants are forms by accumulating particles. Sedimantary rocks are important because the cover the Earth's crust. -
3.5 Billion Years Ago
Lyngbya bacteria began to form into stromatolies. Lyngbya form the basis for the oceanic foodline. Their appearence at such an early period in history is important because they still exist today. -
3 Billion Years Ago
Forms of life became photosynthetic. Photosynthetic life is one of the most important forms of life today. Photosynthetic life is important because it is able to use energy from the sun to produce waste products useful for other organisms. -
2.2 Billion Years Ago
Earth begins to appear as it does today. Volcanoes emitted gas that began to form an atmosphere. The atmosphere develops the blue skies we see today. The atmosphere also is vital for living organisms because it provides air for such organisms to breathe. -
2 Billion Years Ago
Oxygen levels reached a similar level to modern Oxygen levels. Many organisms today thrive off breathing Oxygen. Oxygen 2 billion years ago would be important because it would be able to fuel life. Also eukaryotic cells, a complex type of cell, uses oxygen to live. -
1.5 Billion Years Ago
A type of small aerobic prokaryote began to live and reproduce inside of larger anaerobic prokaryote, this provided a form of energy synthesis called Endosymbiosis. -
1 Billion Year Ago
Ozone formed. This protected organisms from harmful UV rays so they could exist on land. Without Ozone organisms would quickly die out due to harsh ultra violent rays. -
1600's through 1700's
Fransesco Redi noticed and described different developmental forms of flies. He observed that tine maggots turned into sturdy oval cases, which eventually emerge into flies. He also observed that maggots seemed to appear where adult flies has previously landed. -
1900's through Present Day
In the 1950's, scientists used similar experiments to test the hypotheses about the origin of simple organic compounds. In 1970, a broad mixture of organic compounds was found in a newly fallen meterorite. -
1700's through 1800's
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 created an experiment where he boiled broth inside a special flask to prove his hypothesis. -
1800's through 1900's
During the mid-1800's, there was much more controversy about spontaneous generation. The Paris Academy of Science offered a prize for anyone who could clear up the issue once and for all. This prize ended up being won by the French scientist, Louis Pasteur (1822-1895)
