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(5 BYA) Our solar system was a "swirling mass of gas and dust".
Our solar system was a "swirling mass of gas and dust". The beginning before Earth formed -
(4.6 BYA) Earth grew larger and more debris was pulled into our solar system.
Earth began to form into a planet. The debris was pulled together by collisions of debris. -
(4 BYA) The Earth was formed. We use radiometric dating to figure out the age of Earth’s layers of sedimentary rock. Methanosarcina barkeri, a type of Archea, are thought to be similar to the first types of cellular life to populate the earth
Earth was actually formed into a planet that would soon support life. Radiometric dating allows us to figure out when these events happened on Earth. -
(3.5 BYA) Oldest fossils of stromatolites discovered
The fossils provide proof that organsims actually did exist billions of years ago. -
(3 BYA) Some forms of life become photosynthetic
Photosynthetic life provides oxygen to other organisms on Earth. -
(2.2 BYA) Oxygen bonded to other compounds preventing the oxygen from doing damage that it had in the past.
Oxygen had a damaging effect on anaerobic organisms, the bonding of oxygen prevented this from happening. -
(2 BYA) O2 levels reached today’s levels
The oxygen levels we need to survive today reached this point two billion years ago. Allowing life to live on Earth. -
(1.5 BYA) A small aerobic prokaryote was engulfed by and began to live and reproduce inside a larger anaerobic prokaryote
Provided a mutally beneficial relationship for the prokaryotes to survive on Earth. -
(1 BYA) Anaerobic prokaryote, a theory called endosymbiosis
Endosymbiosis may have led to the evolution of mitochondria and chloroplasts, which are essential to life. -
(1 BYA) Ozone (O3) layer formed
The ozone layer was important for life on earth. It proctected organisms from harmful UVA rays, that could damage DNA. -
(1700-1800) Scientists started to use microscopes in experiments
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(1800-1900) Alexander Oparin's experiment
Oparin, along with John B. S. Haldane thought that the atmoshpere contained ammonia, NH3, hydrogen gas, H2, water vapor, H2, and compounds made of hydrogen and carbon -
(1900-present) Harold C. Urey's experiment
Harold C. Urey set up an experiment based on the findings of Oparin. He, in a way, created lightning inside a gas chamber and used the energy to conduct chemical reactions. These experiments led to production of many organic compounds. -
(1600-1700) Redi's experiment
Redi put meat in jars and covered some of them to prove that maggots could only form on meat that flies had previously landed on, going against the theory of spontaneous generation. -
(1700-1800) Lazzaro Spallanzani's experiment
Lazzaro Spallanzani boiled broth in two different flasks and then covered one of them. He observed that the open flask became cloudy with microorganisms while the closed flask was clear. -
(1900-present) Sidney Fox's research
Sidney Fox did extensive research on physical structures that may have given rise to the first cells. -
(1900-present) Thomas Cech discovers ribozyme
Cech used the term ribozyme for an RNA molecule that can act as a catalyst and promote a specific chemical reaction -
(1900-present) Lynn Margulis's suggestion
Lynn Margulis hypothesized that cellular organelles were the result of symbiosis (one organism lives inside another). She believes that mitochondria and chloroplasts were originally separate organisms that became a part of larger cells. -
(1600-1700) Light microscope
Robert Hooke used a light microscope to discover cork cells -
(1800-1900) Louis Pasteur's experiment
Pasteur proved that spontaneous generation was not a possiblity because of his experiment involving a curve-necked flask. When he used the curve-necked flask, the broth inside of it did not spoil. When he broke the top off of it however, the broth spoiled. This proved that the broth was not being altered by a "vital force", but rather the debris falling in it from the top.
