amelius asked why all of our skin does not heal like our mouth. Stating there should be some evolutionary disadvantage "otherwise evolution would have generated

amelius asked why all of our skin does not heal like our mouth. Stating there should be some evolutionary disadvantage "otherwise evolution would have generated mice with faster-healing skin". Evolution does not have some kind of internal bias towards applying past positive mutations in other places, and random mutations are not exhaustive. We have no reason to suspect that a "mouth skin everywhere" mutation has already happened and did not work out. Guided is perhaps not the right term, "goal-directed" being a better one.