I am not aware of any evidence that the problems you mention above have anything to do with inbreeding. In fact, I am aware of efforts that have been made to outcross in order to eliminate those negative traits, but they have not been successful. It seems, from what I've seen at least, that these problems are actually part of the genes that cause the morph, and so they'll be present regardless of how much or how little inbreeding has been done.
Reputable breeders do outcross their animals, but the only way to fix recessive genetic mutations that create the morphs is inbreeding them first. Once you have a line established, then you can add allelic diversity back to counter the diversity lost by the initial inbreeding. You can get away with less inbreeding with dominant mutations, but the temptation there is to produce "Super" forms which carry two of the dominant alleles instead of one, and again the only way to accomplish that is inbreeding. In some cases it may be the morph alleles causing the problem directly, or it may be another gene closely linked to the mutant allele, as seems to be the case in spiders with wobble. Bloodred corns were selectively linebred to enhance the color, which also resulted in smaller, less hardy hatchlings who often refused food.
Some people argue that spiders shouldn't be bred because of the wobble. That's a valid argument, although many people feel that wobbles, especially the milder ones, are not an issue because it doesn't seem to have a negative effect on the snake. However, saying the wobble comes from inbreeding makes no sense based on my knowledge both of the spider morph in particular and how inbreeding problems work in general.
The stargazer gene in corns is totally different. Although it seems to have originally been found in sunkissed lines, it is possible to totally eliminate it by outcrossing and test breeding and eliminating carriers of the defective gene. At least as far as I am aware; I haven't done it personally. I guarantee you, if the wobble could be eliminated from spiders or the other defects you mention could be eliminated from the other lines as easily as stargazer is eliminated in corns, there would be LOTS of BP breeders working hard on doing just that.
I said it was analogous, and meant it in the sense that both impact the snake's movements and orientation, and both are heritable. Stargazer appears to be a recessive allele, while the precise cause of wobble is unknown.
So again, I'd like to see specific examples or other evidence of BP breeders utilizing "really aggressive inbreeding" that has been "degrading the quality and health of the animals", if you have any. I'm not saying it isn't out there. I'm just not aware of it, and if there is evidence of this, I'd sure like to know about it.
A lot of what I have heard/read is anecdotal, and folks are frequently unwilling to throw specific individuals under the bus. Brian Barczyk I believe touched on it in Reptiles magazine earlier this year, I have read an interview from Mike Willbanks discussing the issue in general terms, and I like what the folks at VMS have to say about inbreeding
here.
I think the reason there has been a faster rush to create bigger multigene combos in BPs as opposed to corns is partly because they are more popular right now. But a lot of it has to do with the fact that you can create multigene combos with a larger number of genes in each and every generation, due to the large number of dom and co-dom morphs. In corns, it is slowed down a lot by the need to alternate generations: one generation of hets, and then one generation of visuals. And, the need to breed hets together to get visuals is where inbreeding usually occurs, so I still think inbreeding is probably more common in corns than in BPs.
Based on your most recent post, Guruofchem, it seems like you are talking about unscrupulous breeding in general, rather than careless inbreeding in particular. On that point, I think we are in 100% agreement. That kind of breeder is scum. And yes, there definitely are some of those in the BP world.
Inbreeding may be more common in corns, as almost all the available alleles are recessives, but plenty of the foundation genes in many BP morphs depend on recessive traits - albino, hypo, patternless, piebald, clown, and multiple lines of axanthic are some of the most widely used, and would require the same inbreeding practices to fix the trait in a particular line. Also keep in mind that the gene pool for corns is much broader here in the US than can be claimed for ball pythons, so BPs are starting from something of a genetic bottleneck to begin with.
Anything I've said about irresponsible linebreeding has certainly been done by someone working with any reptile species, but I pointed out balls because of several factors mentioned in my 2nd post - there is potentially more money to be made in balls, investment cost in high quality morphs is higher, and thus there is more incentive to cut corners where breeding stock is concerned and linebreed more than is healthy to get the greatest possible number of desirable offspring in the least possible time. I have heard the issue raised more openly and more commonly regarding balls, which tends to indicate the issue is either more widespread or more problematic or both. Given the much shorter duration of ball python morph development, I would be shocked if more problems than are currently seen don't crop up in the near future - I hope it isn't the case for the sake of the animals, but that's not the way to bet...
