Quote:
Originally Posted by gary
....
Though the fossil record shows they were abundant on Earth 3.5 billion
years ago, today living ones are rare.
|
Stromatolites were certainly around at 3.7Ga and perhaps as far back as 3.8Ga. And keep in mind that these are bacterial colonies and so probably represent a fair degree of development over the original life forms.
I've actually had the pleasure of holding the oldest evidence for life in my hand. Not only that, I took 5 samples from it and analysed them for the carbon and oxygen isotope ratios of the carbonate fraction. The results were published in Nature (
https://www.nature.com/articles/nature19355) - my name appears way down the bottom in the acknowledgements. That's enough to make me happy.