At the most basic level, it means that when a bird has the spread phenotype, it has no visible pattern.
In a previous post I spoke about new research making Dr. Cattanach decided to weigh in on the current debate over the Toller x Aussie outcross and his position is disappointing and uninformed.
Bruce Cattanach said … I am somewhat amazed at the positive responses to this cross. I have had 20 years of vitriol against my Corgi x Boxer cross for every reason imaginable, but I kept it going as I felt that to give up — and so failing — I would damage the leverage it gave to the concept of breed crossing for health reasons.
So the seemingly easy acceptance of the Toller cross is perplexing even if done for a different reason. My analysis against his outcross comes after decades of new evidence and his unwillingness to acknowledge new findings.
Cattanach is seemingly jealous about the positive vibes the dog world has for the Toller cross litter. If I had to estimate why one has been received with more praise I can think of two immediate causes.
Two, this cross was done for much more noble reasons. Cattanach inserted a problematic gene into a breed to avoid a docking ban. However I had great difficulty achieving what I did with just the one gene to be transferred.
It really needed more than one individual to succeed fully. I am therefore quite sceptical about this Toller effort to increase the diversity across the whole genome. Cattanach has really moved the goal posts to an unjust distance in coming out against this one cross.
No one claimed that doing one outcross could accomplish this goal! How about we evaluate a single outcross in a rational manner and judge its power to effect change commensurate with what we should expect from a single breeding.
A single outcross can not save an entire breed, but it can certainly bring in much needed diversity and vitality to a single breeding program, a whole kennel and all the dogs that are bred to that line for several generations.
Any breeder who is disappointed with the options within their breed can accomplish this style of outcrossing themselves. And many more breeders will need to do this before we can claim that Tollers as a breed are refreshed. The LUA Dalmatian project was only one out-cross and the entire breed is not yet free from uric acid problems, nor will it be for many generations to come.
It might just mean that we have to go back to objectively evaluating the dogs we see right before us instead of being overly obsessed with their hidden and mostly irrelevant pedigrees.
I think this needs to be done at a scale only possible at KC level with several crosses perhaps involving several breeds, and then there would be the yet trickier part of keeping the diversity while somehow getting back to breed type.
That numbers of people might independently attempt this is frightening; it could result in no more than a mongrel mix-up. It really should be reserved as a criticism for the Toller breed club and for double-speak geneticists like Claire Wade who put their name on papers which advocate genetic diversity and proactive health measures but then declare zero reason to out-cross in their own breeds and attack those who do.
What good does Dr. Cattanach do by bashing this beginning step? I think he does great harm to anyone who would choose to out-cross for any reason by being so negative. One requires billions of dollars and the greatest minds the world has to offer in an attempt to overcome nearly insurmountable odds.
The other requires two dogs and a little patch of grass. Why must we create political obstacles which make an out-cross more rare than a man walking on the moon?
If superficial out-crosses are the first step, how are we ever going to get to the next phase if the heroes of Step One decide to handicap future efforts like Cattanach is doing here? If we want results, we should try a new strategy, 20 years between out-crosses is long enough. I am sceptical for another reason too.
It almost seems that the Toller cross was done to resolve the high level of inbreeding but if there is no consequent problem of the inbreeding, to my view, the need for the cross does not exist. Is the breed impaired by the inbreeding?
Frequencies of certain defects have been presented but I have seen nothing on the distribution across the breed is the whole breed at risk? If there are indeed problems now or clearly looming, yes, go ahead or at least experiment and see what difficulties there are.
But let this be done in an organised controlled way and on a scale commensurate with that needed. Perhaps he can review my Toller articles and comment.
Recall that Cattanach argued from ignorance before, claiming that there were no side effects from the bobtail gene, that litter sizes were not reduced, homozygous puppies and their problems never lived long enough to be born, etc. None of his assumptions were true and the bobtail gene is decidedly less wonderful the more we find out about it.
We also know that the gene pool is severely limited due to a very very small founding population in the KC dogs.alleles. If a large majority of variation in a phenotypic trait is determined by one locus, the result is a visible polymorphism like Mendel’s pea traits or flower color in Delphinium (Chapter 2).
MENDELIAN GENETICS PROBLEMS AND ANSWERS PROBLEM 1. Hypothetically, brown color (B) in naked mole rats is dominant to white color (b). Suppose you ran across a brown, male, naked mole rat in class and decided to find out if he was BB or Bb by using a testcross. Genetics is a very big field and not everything in it is understood, but we have come a long way in understanding why we are how we are thanks to it.
Answer 2: A trait is a single characteristic that is usually assumed to be controlled by a gene, although many traits are controlled by more than one gene.
homozygote organism that inherits two alleles of the same type for a given gene hybrid offspring that results from a cross between two different types of parents Chapter 6. Gregor Mendel and Genetics.
Mendel’s Investigations. Mendelian Inheritance. Blood is determined by individual combinations of the following gene varieties.I A,I B,and regardbouddhiste.com I A and I B exist together, they make blood type AB (which has 2 . Grade 7 DNA, RNA, and Genetics Having a widow's peak (W) is dominant to not having a widow's peak (w).
Determine the genotype percentage for the offspring of a homozygous dominant female and a homozygous recessive male.