Our solar system was a swirling mass of gas and dust. Most of the material was pulled together by gravity and formed the sun.
(4.6 Billion Years Ago) Gravity Impacts Size
Earth grew larger as gravity pulled in more debris. This is what made the Earth what it is.
(4 Billion Years Ago) Early Cellular Life
Cellular life similar to Archaea lived in this time period. This shows early signs of cellular life which may have led to more complicated organisms.
(4 Billion Years Ago) Creation of Earth
Earth was created, allowing for advances to take places and for the world to become what it is today.
(3.5 Billion Years Ago) Appearance of Stromatolites
Stromatolites, layered structures made from lynbgya cells growing in colonies, were around in this time period. This shows that life was developing and becoming more complicated.
(3 Billion Years Ago) Origin of Photosynthesis
Some forms of life became photosynthetic around this time. This meant that there was another way for organisms to abtain energy, but it also damaged anaerobic organisms.
(2.2 Billion Years Ago) Modern Earth
The Earth's appearance was similar to its appearance today. This signifies that the Earth had fully developed by now.
(2 Billion Years Ago) Abundance of Oxygen
Oxygen levels reach today's levels. This means that oxygen was abundent leading the way for more organisms to evolve and become what they are today.
(1.5 Billion Years Ago) Prokaryote inside Prokaryote
A type of small prokaryote was engulfed by and began to live and reproduce inside of a larger, anaerobic prokaryote. This explains why animals have mitochondria and plants have chloroplasts.
(1 Billion Years Ago) Formation of Ozone
Ozone (O3), which protects organisms from harmful UV rays so that they can exist on land, is formed at this time.
(1668) Redi's Experiment
Redi wanted to test to see from where living things came. He studied meat. He put one piece of meat in one jar and put another in another jar and covered one of them. He noticed that maggots appeared only on the ones that had the open top. This helped to prove that biogenisis was a better theory than spontaneous generation.
(1953) Urey and Miller's Experiment
Urey and Miller tested Oparin's hypothesis. This added support to how life came to be.
(1900-present) Radiometric Dating
This process figures out the age of organisms by measuring the amount of radioactive elements in the organism.
(1900-present) Sidney Fox's Research
Sidney Fox researched the first physical structures that may have led to the first cells. It adds evidence to the question of the origin of life.
(1900-present) Thomas Cech's Experiment
He was able to find out 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
Lynn Margulis researched the possibility that early prokaryotes had a mutually beneficial relationship. This helps support how mitochondria and chloroplasts came to be in animal and plant cells respectively.
(1600-1700) Early Microscopes
This new innovation allowed scientists to be able to make observations of tiny organisms that the naked eye could not see. This would lead to many new scientific discovery, including that of Robert Hooke.
(1700-1800) Spallanzani's Experiment
Spallanzani further tested Redi's hypothesis and boiled two flasks of broth. He then put a lid on one of the flasks and the other remained open. After a while of experimenting he found that the open one contained microorganisms and the closed one did not. This further helped to support the theory of biogenesis, where living things are thought to come from other living things.
(1800-1900) Pasteur's Experiment
He wanted to further support Spallazani's findings by making a variation of the experiment that would not attract the controversy of the "vital force" not being able to get in. He further supported the theory of biogenesis.
(1920s) Oparin's Hypothesis
Oparin Hypothesized that heating up the gases that existed in the early atmosphere formed simple, organic compounds. This would lead to future discoveries about the origin of life.