-
(5 bya)
the solar system began to form -
(4.6 bya)
the earth began to form and it grew by colliding with space debris -
(4 bya)
the space collisions into the earths surface stopped -
(4 bya)
organic molecules began to accumulate -
(3.5 bya)
stromatolites began to emerge -
(3 bya)
some forms of life had become photosynthetic -
(2.2 bya)
the earth probably appeared much as it does today -
(2 bya)
O2 levels reached today’s levels -
(2 bya)
an early form of aerobic respiration was formed -
(1.5 bya)
the first sign of endosymbios, a prokaryote living inside of another -
(1 bya)
Ozone (O3) formed – protected organisms from harmful UV rays so they could exist on land -
(1 bya)
eukaryotic cells began to evolve -
Between 1600 -1700
francesco Redi used an experiment to show that maggots dont grow from meat they grow in meat -
Between 1700-1800
the first microscope was invented and it allowed scientist to observe that their world was full of tiny microorganisms that were everywhere -
Between 1800-1900
Louis Pasteur’s experiment was so soild that the debate of spontaneous gerantion was ended without and argument ( he did Spallanzani’s experiment but left the flask open and had a curved neck on it to catch dust. -
Between 1900- present
a mixture of organic compounds was found on a meteorite suggesting that
that compound formed in space so organic compounds could have accumulated on the surface of early earth
thomas cech discoved ribosomes and other roles that rna has.
Lynn Margulis proved that the theory of endosymbiosis was correct with her experiments -
Between 1700-1800
spallanzanis experiment correctly disproved the theory of vital force by heating two flask and sealing one to see if there was vital force but only the open flask became cloudy but his opponents objected to his idea saying there was flaw in his experiment -
Between 1900- present
radiometric dating is discovered. this allows scientist to accurately tell the age of an object by looking at the number of a particular radioactive isotopes a material has to determine its age oparins hypothesis states that the gases in the earth early atmosphere, at high temperatures, might have formed simple organic compounds that could have resulted in the formation of macromolecules essential to life, such as proteins. miller and urey proved Oparins hypothesis was possible and it did
