The life timeline By Vilardaga 4500 BCE Earth's formation 4000 BCE The first organic molecules 3500 BCE Life appears. Prokaryotic cells. 1800 BCE Oxygen in the air 1400 BCE First Eukaryotic cells 600 BCE Multicellular organisms. Cambrian life's explosion 500 BCE First vertebrates 200 BCE Dinosaurs and mammals coexist 65 BCE Dinosaurs extinction... Primates 4 BCE Austrolopitecus
