Oh boy genetics.... Now I know that tune, who wants to dance??
To be clear here we are talking about genes and not genetics. Genes, in and of themselves, do not "want" anything. A gene is nothing more than a unit of information, it has no "wants" or "goals".
A mutation is no more "bad" than it is "good". A mutation simply is. However, how that mutation effects the organism can be said to be "bad" or "good" but that is totally arbitrary depending on who/what is making that determination. For example, most everyone would agree that Sickle Cell Anemia is "bad" and yet, in parts of the world where malaria is rampant, being a carrier for the Sickle Cell gene gives you a resistance to malaria which most people would say is "good". So, is Sickle Cell "bad" or is it "good"?
You cannot say that they weaken the species, I am sorry Scot. You are putting a trait on genes that simply is not there, basically you are personifying them. I am tired of the "good"/"bad" label because it simply is not applicable so let me use what geneticists use: "Fit", which brings us also to one of the single most misunderstood ideas in genetics/evolution, the idea of "Fitness".
A gene is "fit" only in relation to other variants (alleles) of that same gene it has nothing to do with the organism as a whole or how that gene relates to other genes.
So, genetically speaking, Wacky Traps (aka Bart Simpson) and Pugs and Persians and Parrot cichlids are all very much genetically fit because the genes for those traits have survived the process of selection. I grant you that that selection was at the hand of "man" and not "nature" but that simply does not matter.
The species in and of itself is not weak. There are numerous other alleles of those genes out there and if the selective pressure switches then the unfit genes will be culled from the population and new ones will take their place.
Again, genes do not want, they simply are. You must quit personifying them.
And for the record, cancer is actually the ultimate in fitness from a genetic stand point. Immortality is the ultimate in "self-preservation".
Just because a mutant gene is present in a pool does not by default mean that pol is weakened. Again I point you back to the Sickle Cell gene, outside of malaria regions it is not a fit gene but within those malaria areas it is most certainly a fit gene, and purging it from those populations would actually hurt them. I can think of many other cases where the presence of a mutant gene actually ended up conferring a fitness unto a population by its presence.
So, you cannot correctly say that mutant individuals will, by default, harm the population.
That argument does not stand up to reason though. There are perfectly normal looking plants from perfectly normal looking parents that are in no way genetically related to "cup traps" and yet harbor "weakness" genes and could produce weak offspring. Whether a plant grows weakly is likely not the result of a single gene. Every year people are producing plants from crosses where they sow the seed out and a few years later the weak plants have died or been pulled but the strong plants are sent out to others likely carrying some of those same genes that made their siblings weak. And yet no one baulks about that.
The example hits a flaw though. While you may not like those genes popping up in your collection some one else may. I can relate this back to a snake breeder who bred a couple snakes together looking for one result (piebald) and got out another (piebald, axanthic and piebald axanthic). He was not aware that either snake carried the axanthic gene but he was thrilled to discover they did.
When we are dealing with such things as "desirable" mutations there is always a level of subjectivity on what exactly is desirable. You do not like cup trap and I do. I do not like fused tooth and you do. So what happes is that I do not breed fused tooth plants and you do not breed cup traps and some people will want my plants and some people will want your traps and then one day someone who wants a fused tooth cup trap will get both of our plants and breed them together and get something new and unusual that will rock the VFT community. So while we each have our dislikes the genes behind those dislikes still have their fitness under the selective pressure of the collector. No "good". No "bad".
Well said Pyro, i couldnt have come near to saying it any better myself!