The question of how life came to be on this planet is one I can't answer. It's something scientists are working on, its called abiogenisis. However we have created in a lab, the building blocks of life from non life. So essentially, life from non life is very possible. This question doesn't effect evolution though because evolution is a process that life goes through [i][b]after it already exists[/b][/i]. Just something important to keep in mind.