History of life on Earth By 11BIO3 4600 BCE Formation of Earth Period: 4600 BCE to 4000 BCE Hadeon Eon 4500 BCE Loss of Earth's atmosphere 4404 BCE First appearance of liquid 4280 BCE Earliest appearance of life Period: 4000 BCE to 2500 BCE Archean Eon 3500 BCE Lifetime of the last universal ancestor 3500 BCE First procaryotes 3000 BCE Evolution of photosynthesising cyanobacteria 2500 BCE Great oxygenation event Period: 2500 BCE to 542 BCE Proterozoic Eon 2000 BCE Diversification and expansion of acritarchs 1500 BCE First eucaryotes 800 BCE First multicellular organisms 750 BCE First protozoa 650 BCE First soft-bodied organisms 600 BCE Formation of ozone layer 570 BCE First arthropods evolve Period: 543 BCE to 1 CE Phanerozoic Eon 540 BCE First trilobites 530 BCE First fish 475 BCE First land plants 410 BCE Fish become abundant 385 BCE First forests 370 BCE First amphibians 350 BCE Earliest reptiles 225 BCE Evolution of dinosaurs 208 BCE First birds 200 BCE Evolution of mammals 130 BCE Evolution of flowering plants 100 BCE First bees 65 BCE Mass extinction 65 BCE Dinosaurs and ammonites become extinct 60 BCE First large mammals 14 BCE First great apes appear 2 BCE Genus homo evolve
