Natural Selection

I don`t have a clue what the definition of the natural selection theory is, but watching the film I suppose that from the moment of the birth we have made selections unconsciously and that`s what the title of the film was trying to say.For instance,we know who the father or mother is without deep consideration for most of the cases.Therefore, I think the film was trying to assure us that we don`t have a control over everything,albeit our life is formed by those things.