Originally Posted by whistlepig
I do get what you are saying here, and if it does negatively effect an animal's health in captivity then I am with you. I'm only adding two additional caveats. First that from a "natural" perspective there is little difference between color mutations (here I'm talking about mutations that would make the animal stand out in it's natural environment) and missing scales. Both mutations are traits that would be strongly selected against outside of captivity. Second that if scale-less snakes are a desirable trait, which judging by the poll and responses here must be an extremely small group of people, that animals with that trait will survive and reproduce in captivity, making it a "successful" mutation at least within the community of pet owners that like them. I think what you are arguing is that because it causes problems for the animal that it shouldn't be done, an ethical issue which I agree with.
True, but it's not like there's no precedent for reptiles losing their scales, they've done it at least twice. Once for the lineage that eventually became mammals, and the second for the lineage that eventually became birds. I suppose you could argue that feathers and hair are modified scales and therefore they didn't technically lose them, but it did look like those snakes had some rudimentary scale-like structures as well.
Well this is sort of true. While many of those groups look the same today as they did millions of years ago, they have undergone some changes which is why there are so many different species and subspecies, but true that their form generally works well in the environments in which they're found. In the grand scheme of things though a snake lacking scales that could live and reproduce only in captivity isn't much different than any other recently evolved species. While the differences are highly visible the general form of a snake is maintained.
There is a huge difference, evolutionarily and in time scale, between a trait that has remained relatively unchanged for an entire class of animals to one that is not consistent even with animals of the same species. Feathers and hair are definitely modified scales and in either case they did not give up protection these structures provide them. A scale-less animal is more prone to injury and infection, even in captivity.
Now amphibians actually lost their scales, from fish, to better take in air, it is hypothesized. Of course as more efficient lungs were evolved they regained these structures, again proving their importance.