What are you talking about?
Certain individuals have an adaptation of "no Wisdom teeth" - it is not necessary for the species to have no Wisdom teeth at all, for it to be thought that people without them are evolved?
No. The "no wisdom teeth" is a variation. If a variation conveys some reproductive advantage, it can be called an adaptation, since it is making the individuals with that variation better adapted to produce offspring.
In the case of "no wisdom teeth", this would be an adaptation, since wisdom teeth can cause many problems which can conceivably reduce the chances of reproducing.
But it makes no sense to say that if all Humans had the "no wisdom teeth" variation that they would be a different species than those who do have them. That kind of difference is just way too small to count as a different species. Generally speaking, the change has to be large enough that two individuals can't reproduce in order for them to be called a different species.
For example, I never got wisdom teeth, but my husband did. Yet, we were still able to produce a child together.
So, if two individuals don't produce offspring (whether it's because they are just not genetically compatible, or more rarely, because they do not give out the right behavioural or visual signals), they are different species.
What you are saying makes sense if you say "some people have no wisdom teeth but others have very good dentists, so the point is moot" - but even then you are dodging the link, rather than theorizing with it.
As I said, the "no wisdom teeth" example is so small that it makes no difference when it comes to making a different species.
I always thought adaptation was an outcrop of resistance to mutation - that's how it is typically sold: you are saying you can stop saying the word adaptation and it won't affect what actually adapts? I don't buy that.
Where did you get the idea that "adaptation" meant "resisting mutation"?
An adaptation is a mutation (also called a variation) that helps an animal to survive and reproduce.