Galactic Year Timeline

Timeline of earth's history in galactic years
In this list, 1 galactic year (GY) = 225 million years
 * 0 GY: Birth of the Sun
 * 4 GY: Oceans appear on Earth
 * 5 GY: Life begins
 * 6 GY: Prokaryotes appear
 * 7 GY: Bacteria appear
 * 10 GY: Stable continents appear
 * 13 GY: Eukaryotes appear
 * 16 GY: Multicellular organisms appear
 * 17.8 GY: Cambrian explosion
 * 19 GY: Great Dying
 * 19.6 GY: K–T extinction event
 * 19.999 GY: Appearance of modern humans
 * 20 GY: Present day