Oldest fossil

This is a recent discovery by a team of Australian researchers working in Greenland near the Greenstone Belt along the edge of Greenland's icecap. What they found is 3.7 billion year old stromatolite fossils in ancient sedimentary rocks that date from that far back in time. The fossils that they found predate the oldest found in Australia.

Stromatolite is represented by mounds of carbonate material created by ancient single-celled creatures that lived in rock that became sedimentary (layered) over time. The reason that these colonies of ancient creatures have become visible is because of melting caused by climate change. The official name for these creatures is ISB (Isua supracrustal belt) microbial communities. These ancient microbes grew in a shallow marine environment. This is evident because the rock layer metacarbonates contain seawater rare-earth elements and yttrium.

The reason that this is important is because it moves up the earliest date for life formation on the planet Earth. The present accepted age of the Earth is 4.54 billion years. Thus, in less than a billion years life appeared. That throws some theories about how life formed out the window. For one, the late great bombardment period occurred at 4.1 billion years and ended at 3.8 billion years. That means that life formed only a hundred thousand years later. That would suggest that the Earth had to cool down fairly rapidly after the bombardment stopped and then allow life to form in the oceans.

The collision of a Mars-sized planet that formed the moon occurred at 4.48 billion years, so life didn't form till after that incident.
I would suggest that life didn't spontaneously occur on Earth. There wasn't enough time. I think that this would strongly suggest that life came from outer space, possibly from Mars. This strengthens the idea that we're Martians. Although, there are theories out there that suggest that life could have originated on Venus. Keep in mind that Venus was once like Earth with oceans and a reasonable climate.

Thanks for reading.