First Life on Earth: A 4.54-Billion-Year Timeline

Drag the slider, or tap a milestone, to see what life on Earth looked like at any moment from the planet's formation to today.

Earth's age
O₂ in air
Dominant life

How we know
Dates follow the 2024 International Chronostratigraphic Chart and recent peer-reviewed work. The LUCA date is from a 2024 molecular-clock reconstruction; the oldest widely accepted body fossils are the 3.48 Gyr Pilbara stromatolites. Atmospheric O₂ values before the Great Oxidation Event are upper limits set by sulfur-isotope evidence. Proterozoic O₂ levels carry wide uncertainty.
Sources