Period 5, Nguyen, History of Earth By 2013nguyenba Jan 1, 2011 5 BYA, SUN FORMATION Sun was established by a Mar 14, 2011 4 BYA, firsr cell life ( Prokaryotic ) Mar 26, 2011 3 BYA, First Photosynthetic cells - make oxygen Apr 20, 2011 3.5 BYA, First fossils of prokaryotic bacteria Jul 24, 2011 2.2 BYA, Earth looks like it does today ( land and oceans ) Aug 7, 2011 2 BYA, Endosymbiosis makes eukaryotic cells Oct 9, 2011 1 BYA, Oxygen in the air makes the ozone layer Nov 29, 2011 4.6 BYA = EARTH FORMATION Dec 31, 2011 Experiments in the 1600's, Redi, Spallanzani, Pasteur