Have scientist made life from these "gases that existed in earths primitive atmosphere". Not even close!
Miller excluded oxygen in a reduced atmosphere because life could not evolve with oxygen present. Any amino acids that try to combine are "oxidized". He used methane, ammonia, water, vapor and hydrogen. This creates a serious problem, because ammonia is destroyed by UV light. And UV light must be blocked by ozone which is made from oxygen. See the probblem?
Dude, this was testing hypotheses on abiogenesis, not the Theory of Evolution.