First Prokaryotes On Earth. Eukaryotes only appear in the fossil record later, and may have formed from endosymbiosis of. Based on fossil evidence, prokaryotes were the first inhabitants on earth, appearing 3.5 to 3.8 billion years ago during the precambrian period.

For many years they were the only life on earth until around 1.5 billion years ago when the prokaryotes evolved into eukaryotes. The domains bacteria and archaea are the ones containing prokaryotic organisms. Scientists that study cells believe that the appearance of the first prokaryotes on earth was around 3.5 billion years ago.