Natural selection is when the animal dies from reasons out of our hands, not if we just kill breeders because one died. Asfs are also a totally different thing than normal rats. Id trust mike with anything to do with ASFS, but I have delt with hundreds of litters with normal rats so I know a fair bit about what should be done and what not.
Mike, are we talking about the same thing here? Im saying if in a breeding group, an established one, if one of the breeders dies...you'd kill all of them? I never keep bad breeders, and normally my breeding groups are unrealted to the other rats in the tub so they are never from the same litter, so any bad genetics would not be a problem with the others if it is with one.
I think your saying that if you lets say have a group of 1.2 and a female dies...youd just get rid of the whole group because 1.1 really is a waist of space.
I normally keep 1.4... so if one gos I either replace it or just keep 1.3 going because that will produce plenty enough pinkys. Maybe thats where we are confused, because if something happens to one of mine I still have a good group going, but if something happens to his he only has one female.