I personaly believe butters and lessers are just different blood lines of the same gene, kind of like Axanthics. Butters do look to be a bit more hypo from what I have heard.
I also believe that lessers and butters, mojaves, phantoms are basicly different versions of the same gene but happen to be on a different loci (in other words the "damaged" gene is the same, but happens to be on a different chromosome)
But I don't really have a way to prove this and may be totaly wrong![]()