Hi All

There are still geoscientists arguing over when the oldest verifiable lifeforms are to be found in the rocks. No indisputable microfossils appear until after 1.9 billion years ago. Everything earlier can potentially be explained via abiotic processes, though there are a lot of strong hints of earlier life even back to 3.85 billion years ago. Molecular clock data suggests a common origin for life at about 2.0 billion years ago, which also bolsters the late arrival view.

So panspermia looks better and better the shorter our tenure on this planet. Perhaps we're all derived from refugees from Venus? Or from even further afield.

However even the diehard sceptics of Archean biology think life appeared c. 3.8 - 3.5 billion years ago - they just want to prove it. So maybe the circumstantial evidence is correct. Some decent microfossils would be good.

Adam