But even this article says there was no real evolution for 600 million years before the “Cambrian explosion”.
Isn’t that suppose to be impossible?
Well... the article says: " For about a billion years after the dawn of life on Earth, organisms didn't evolve all that much.
Then about 600 million years ago came the 'Cambrian explosion.' "
"All that much" is a matter of opinion from people of obvious bias towards multi-celled critters.
But those who love single-cells could doubtless point to many exciting changes over those short billion years. ;-)
Second, while the Cambrian itself was "only" about 20 million years long, starting aroung 540 mya, the "explosion" actually began 60 million years before that, and lasted another 70 million years beyond -- so we are really talking about 150 million years of "Cambrian explosion".
I mean, really... "150 million years" only takes a second or two to say, but it's a very long time indeed, once conditions for evolution are just right