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(5 BYA) Solar System
The solar sytem began to form. -
(4.6 BYA) Formation of Earth
Space debree swirled around the sun, and started to compact. More debree would circle around a center point that had the most build up, gruadually creting the Earth. -
(4 BYA) Earth
Collisions with space debree ceased, the Earth began to cool to a temperature much closer to what it is today. -
(4 BYA) Life
Organic molecules began to cluster together. -
(3.5 BYA) Cells
Cells began forming layered structures called stromatolites. -
(3 BYA) Life Surges
Cells develop the abilities to photosynthesis and breath. -
(2.2 BYA) Earth Again
Earth probably appeared much as it does today. -
(2 BYA) Earth's Atmosphere
O2 levels reached today’s levels. -
(1.5 BYA) Eukaryotic Cells
A small prokaryotic cell was engulfed by a bigger cells. instead of being digested, the two cells began to function together. Eventually they reached the point where they were useless without each other. -
(1 BYA) Ozone
O3 began to form around the Earth, protecting organisms from harmfull UV rays, and allowing them to live on land. -
(1668) Redi's experiment
Redi showed that rotting meat kept away from flies would not produce new flies. -
(1768) Spallanzani
Spallanzani showed that microorganisms would not grow in broth when its container was heated and then sealed. He inferred that microorganisms are carried in the air and do not arise by spontaneous generation. -
(1800's) Pasteur
Pasteur in the 1800’s used a variation of Spallanzani’s design to prove that microorganisms are carried in the air and do not arise by spontaneous generation. -
(1905) Radiometric dating
Invented in 1905 by Earnest Rutherford, is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates. -
(1942) Oparin’s hypothesis
Aleksandr Oparin hypothesized that the formation of amino acids and proteins from non-living chemicals, a process known as "abiogenesis", could have occurred in the conditions present shortly after the formation of the Earth. This process would not be observable now because other organisms would absorb created proteins, which would be rare anyway due to the higher concentration of oxygen in Earth's current atmosphere. -
(1952) Urey and Miller
Showed that chemical reactions on an early earth would have favored that synthesized organic compounds from inorganic precursors. -
(1964) Sydney Fox
conducted extensive research on the physical structures that may have given rise to the first cells. -
(1966) Lynn Margulis
theory on how eukaryotic organelles developed is now the generally accepted one. -
(1970) Thomas Cech
showed that life could have started as RNA -
(1665) Microscopes
Early light microscopes were used to study nature. Coutnless microorganisms are discovered.
