after the earth formed, it says here:
Scientists analysing Australian rocks have discovered traces of bacteria that lived a record-breaking 3.49 billion years ago, a mere billion years after Earth formed.
If the find withstands the scrutiny that inevitably faces claims of fossils this old, it could move scientists one step closer to understanding the first chapters of life on Earth. The discovery could also spur the search for ancient life on other planets.
These traces of bacteria "are the oldest fossils ever described. Those are our oldest ancestors," said Nora Noffke, a biogeochemist at Old Dominion University in Norfolk who was part of the group that made the find and presented it last month at a meeting of the Geological Society of America.
One thing that I find fascinating about this is that the cyanobacteria they're discussing are responsible for the first mass extinction: they're the ones that started pumping oxygen into the atmosphere and killed off all their anaerobic brethren.
But still -- "a mere billion years"? I guess it all depends on your point of view.
Something to think about.