How strong is the evidence of early Earth for living cells before 3.4 billion years ago?




• The evidence is still controversial, but there are both microfossils and isotope data suggesting the existence of cells from rocks older than 3 4 BYA.

• The evidence is strong that there were NO living cells before 3.4 BYA because isotope analysis cannot find fixed carbon-12

The evidence is weak because there are only biomarker molecules found in rocks older than 3.4 BYA and no fossils of any kind

The evidence is indisputable because there are clearly detailed microfossils older than 3.4 billion years as well as isotope and biomarker data.