Sorry - I don't buy the evolution analogy. There's elements of it that match but here's the issue. In a free market, companies don't 'evolve' to innovate. Innovation isn't the end goal, surviving and profiting is. There's a hell of a lot of ways to profit other than innovation and innovation is always a risky strategy to reach that end. Often it's easier to make a measured approach and plan to drag down anyone else who innovates, especially once you're big enough.
A free market is about the profitability and survival being the end goal and whatever achieves that is what happens. This is why licensing is required, to ensure that people don't get trampled underfoot on the way to that profitability.
As Solandri stated, licensing applies to people who could endanger your wellbeing through incompetence or negligence and we all benefit from that. You _could_ argue that people can vote with their feet, avoid restaurants that develop a reputation for food poisoning etc. Noone wants to be one of the ones who dies on the way to building that reputation, though.