The oldest proven evidence for life on earth is from Stromatolites dating back 3.5 billion years. This is one billion years after the formation of the earth, and 3 billion years earlier than what was long thought to be the origin of life (The Cambrian period, ~500M years ago)
Stromatolites in Saudi Arabia
Connections
Reference
It’s Time to Rethink How We Study Life’s Origins. It Emerged Far Earlier, and Far Quicker, Than We Once Thought Possible