I established before that Brackett’s formula is a rather non-unique scheme, producing at a minimum a puppy that is 6.25% inbred with the desired ancestor representing 37.5% Blood and a matching Genetic Covariance.
There are numerous other schemes that will produce the exact same results. In fact any 2:3 inbreeding (representing that the key dog is in the second generation on the sire side, third generation on the dam side) or 3:2 inbreeding would produce the same numbers.
The only thing unique about this particular version is that when the key dog, “Studley,” is the sire’s sire we have a conservation of the sire line, specifically the “y” sex chromosome, also known as an allosome.
An allosome is a sex chromosome that differs from an ordinary autosome in form, size, or behavior. The human sex chromosomes are a typical pair of allosomes. The x chromosome is present in the ovum, while x or y chromosomes can be present in sperm.
While this might be desirable to capture the specific genetics of that sire in the allosomes which do not recombine, the overuse of this formula and the sexism of the popular sire effect means that many breeds have vanishingly few sire lines at all.
This is one avenue where diversity can be swiftly lost and sex linked diseases can crop up very fast, undetected by COI calculations. Many sex linked diseases are also easier to express as “carrier” status (the disease appearing on the X sex chromosome) can result in full disease expression.
Although Brackett doesn’t acknowledge that his scheme isn’t all that unique, he does give the breeder permission to make subtle “modifications” if they can’t find suitable breeding stock to fit his precise formula.
In the absence of a stud with such bloodlines, those with modifications of it can be used. As one example amongst many, the sire of the sire might be the grandsire of the dam on the SIRE’S side, instead of on the dam’s.
This modification makes absolutely zero difference. If anything, it gives us another glimpse of the Y chromosome characteristics from our Studley key dog in the form of Butch (was Bitch in the original formula), seeing as Bitch couldn’t display these genes as she wouldn’t carry them. The resulting puppies, however, would be indistinguishable under this alteration.
Brackett presents this identical scenario under the assumption that the ideal blood lines are not available. This suggests that Brackett doesn’t understand basic genetics, at least not enough to realize that this isn’t even a variation on his stated formula in any meaningful way.
His last explicit example, however, significantly changes the genetics.
Another: the sire selected might be the result of either a full or a half brother and sister mating, and thus inbred. And so we might go on listing differing formulas indicating inbreeding and line breeding.
While not changing the formula, here Brackett wholeheartedly endorses very close inbreeding. And we see the result in the Genetic Covariance. I’ve replaced Studley with the 25% inbred Dudley (brother x sister, as suggested).
You can see that having a highly inbred stud dog to start with increases the Genetic Covariance–the degree to which the puppies will look like that ancestor–from just over one third to just under one half, almost as much as a normal parent. This is a significantly more potent scheme to express Dudley’s genes in the puppies, but Brackett fails to put this in any context or establish how significantly different these results would be from his standard formula.
And that’s sort of the point. Why is 37.5% Genetic Covariance optimal? Why is it better than 25% or 50%? What factors are we really weighing here and what is the counter factor to inbreeding?
Brackett gives us none of these things. He doesn’t explain why this formula is optimal. He doesn’t show us why he settled on a 2-3 generational inbreeding versus any other type. For this to be a legit theory or formula, the burden of proof is on Brackett to establish the testing methodology and the optimization calculation.
All he gives us is that he likes this formula and that he’s raised a lot of show champions in a short amount of time. This sort of logic is attractive to morons and monsters who can breed and laud a dog so ugly and dysfunctional as to be a joke. A cruel, unforgivable joke. And yet they smile, instead of laugh, give rosettes instead of scorn, and they are adamant that they are creating an ideal dog.
And Brackett gave them a formula for success in destroying this once noble breed.
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