There is a theory that complements the theory of evolution, but rather complements it begins and ends when the evolution begins.
There is a theory about the beginning of life, that first moment where form.
There are many theories about this time, the scientific as I describe now, and theological of which I will not deal in depth, because this is not dogmatic scientific blog.
The theological theories basicamante what they reveal is that life arose spontaneously and randomly, but by the intervention of an "entity" or god who was in charge of putting the first bricks.
The theory of abiogenesis what it describes, in a summarized way, is that at the beginning of the Earth, once calm early as a planet and then to calm and stabilize the crust, in the prebiotic soup were the chemical elements necessary for the spontaneous generation of life. There was no intervention of "third parties" only chemical and forces of nature acting in unison, to create those conditions that led to the first form of life, and the theory of evolution is responsible to explain.
I show you a very interesting video on this theory, which explains everything in a simple and didactic way