Where did prokaryotes come from?Simple cells, prokaryotes.
"Most likely" - Meaning you don't know for a certainty?(Most likely)...
(1.) These are the theories yes, and I have no problem accepting those looking at these things want to know the same things the average person does in terms of how life began, I find it interesting.(1.)Officially since bacteria developed primitive forms of photosynthesis which at first did not produce oxygen, about 3500MA ago. But before that, the formation of Greenstone belt of the Isua complex of the western Greenland Region, (2.)whose rocks showed an isotope frequency suggestive of the presence of life.
(2.) Terms like "suggestive" are commonly used in evolution theory largely because there are holes that can not be explained. That is all I am saying.
But not all organisms right? I mean, you can't say that with absolute definity when there is so much about our own earth, much less the entirety of the universe that hasn't been scientifically proven.There is no "need" for evolution - it is an inevitable result of the way organisms are constructed and the way they reproduce.