where did the first life come from then?
It's an interesting question, but one we can't answer for a very simple reason. Mars rock aside, we don't know if life (intelligent or otherwise) is unique to Earth.
As such, it becomes a little hard to say with any certainty that life on Earth arose by X or couldn't possibly have arrisen by Y.
The universe could be absolutely chock full of life, or it could be a vast waste land.
Either way, how life got here (whether created by a mystical force, created by a mishap of chemistry or arriving here from elsewhere) is not of great concern to Evolution.
If we were to transplant life onto Mars and left it alone for millions of years, we'd expect evolution to continue taking place. Evolution is a process of life, but not the progenitor of it
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