You are confusing adaptations with evolved species. By your definition a redhead is a different species than a blond person. Where did life come from?
We now have ways of studying evolution using DNA as well as visual characteristics. For example, the redhead is more likely to have Neanderthal DNA than the blond. Unfortunately, we cannot study the DNA of very old fossils to see how new genes have mutated and thus there could be a gradual shift in DNA percentages until a quite new creature has appeared.