Genetic Diversity

[JTG]

Genetic law:
"It is not the strongest of the species that survives, nor the most
intelligent that survives. It is the one that is most adaptable to change."
Most of the older breeders and now, the newer breeders discourage linebreeding or inbreeding, as an attempt to increase breed genetic diversity. This position is based on a false premise and guess work that misinforms with their teaching and writings, based on guessing instead of science. They simply lack the knowledge and skill, based on their methods it would take many years of breeding with constant whole litter culling every three years to have very little measurable improvement. They have no real results other than the passing on average or below average offspring and spread genetic defects. Improvement is slow if at all and is based on the results of the offspring which pass on undesirable genes. Inbreeding or linebreeding does not cause the loss of genes from a breed gene pool. It occurs through selection; the use and non-use of offspring. If some breeders linebreed to certain dogs based off of measurement, and others linebreed to other dogs to a similar standard, then breed-wide genetic diversity is maintained.(One of the many reasons why breeding to a standard is important.)
With the old timey guess methods their dogs who are poor examples of the breed and should not be used simply to maintain diversity are bred. But instead they encourage and misinform with their writings and breed the same. Related dogs with desirable qualities will maintain diversity, and improve the breed. Breeders should concentrate on selecting toward a breed standard, based on improvement that can be measured. Using progeny as the ultimate measurement of improvement.
The poor choice of selection, the real cause of genetic health problems. It has been shown that some inbred strains of animals thrive generation after generation, while others fail to thrive. If there is no diversity meaning the gene pairs are pretty much the same in both parents and are non variable but the (homozygote) or genes that are present are not detrimental, there is no effect on breed health. The characteristics that make a breed reproduce true to its standard are based on non-variable gene pairs, not the current guessing method.
JTG
Purging inbreeding depression and the probability of extinction: full-sib mating.

Hedrick PW.


Source

Department of Zoology, Arizona State University, Tempe 85287.


Abstract


Inbreeding depression has been a topic of interest in recent years from a number of perspectives, particularly in the captive breeding of endangered species. Generally, the goal of captive breeding is to avoid the detrimental effects of inbreeding depression and to retain genetic variation for future adaptation. However, an important component of another suggested approach to captive breeding is to purge rapidly the population of its genetic load so that its long-term fitness is not compromised. I have examined the effectiveness of purging the genetic load by documenting both the reduction in inbreeding depression and the increase of the probability of extinction when there is continuous full-sib mating. When the genetic load is the result of lethals, the inbreeding depression is quickly purged without a high probability of extinction, except when the total genetic load is high. On the other hand, if the load is due to detrimentals of relatively small effect, the genetic load becomes fixed, the mean fitness is reduced, and the probability of extinction may be greatly increased. In other words, the success of such a programme to purge genetic load without an increase in the probability of extinction is highly dependent upon the genetic basis of inbreeding depression, information that is not readily available for most species.


PMID: 7989216 [PubMed - indexed for ME

[pegleg]

It interest me to see actual research examples and their results. However not all species respond to genetic purity or lack of the same way. Also its worth remembering we don't always rate genetic effects the same as nature appears to. Often genes and their resultant changes seem important to us but have little effect in expression. And of course the mirror image is just as likely in other cases . This requires us to watch closely all of our trials and to be open to the possibilities. The more complex a animals genetic makeup the more possible combinations there are to achieve similar results in observation . However a shrew isn't a mouse and that can be said for many animals. Which leaves everyone not able to map complete genomes with nothing but guesses observations and as those vary its hard for us to progress in a breedned when basic variables like size are taken to be important and other linked traits condemned arbitrarily

[cobalt]

Does MHC (major hystocompatability complex) figure in to the equation with this type of heavy inbreeding where the benefits of heterozygosity are imperative to long term survival?
From what I've read of the studies done, the possibilities are probable, but the probabilities are minimal for success, even with high serial populations in labratory conditions. Depending on the species and its complexity, there is always a downward swing towards inbreeding depression for several generations before it gets better. Success is often gauged by the recovery of the test group towards what the health of original outbred animals was.
The "theory" of the success of this process is interesting to say the least, but considering it takes so much data through DNA testing to make sure all is going right, it doesn't seem practical at this point especially because it has never been done with working animals (or wild animals) and is studied heavily because of the captive breeding of endangered animals like certain species of tigers whose genetic bottlenecking threatens their existence and is a theoretical way of maybe saving them, but is NOT being practiced. Other factors include the lack of ability to map DNA completely in any mammal including humans and the issue of how we as humans have impurified the sanctity of domesticated animal's DNA in the first place. Probably irreversable unless we started over.
The last sentense of that article says a lot: "In other words, the success of such a programme to purge genetic load without an increase in the probability of extinction is highly dependent upon the genetic basis of inbreeding depression, information that is not readily available for most species."





PMID: 7989216 [PubMed - indexed for ME[/quote]

[slowandeasy]

JTG,

I think by now you know where I stand in regard to breeding practices. That being said, for those that don't. I will probably stand by the practice of line breeding with the main goal of inbreeding till they spread my ashes around the country.

Although I don't base my conclusions from reading every study or scientific experiment(proof). Mine simply comes from a dad that also believed in line breeding with the end goal inbreeding. And actively participated breeding hounds for probably 50 to 60 years. And at age 57. Although I have been around them, since seven years old. I probably didn't start to be intrigued with breeding until age 17. Which adds about 40 years, to the possible 90 to 100 combined.

I guess the reason I'm so bullheaded in my preference toward this particular practice. Is really not from quotes or other experiments. Done by people that talk a really good line. It simply comes from results seen with my own two peepers.

This being said, I have also seen litters that have produced superstars. And gone back to do the same cross. Only to have a couple of culls, and fair to midlin individuals. Talk about wanting to bang your head on the concrete. But overall, the results were always overwhelmingly for the most part, positive. This not only based on the percentages that we kept. But from people within the circle that we farmed pups out to, and also by countless letters from satisfied people who purchase pups from us through the years.

Although I'm readily willing to admit that there sure is no concrete answer as to which way to go. I do sincerely believe, that after rubbing elbows with many people in the hound world that we have had the pleasure of meeting. I do believe that the method of line breeding has produced more success through the years. Than randomly picking hounds of unrelated ancestry and hoping to get the right mix. And also feel, that if people were being honest. If you started your breeding program that way. And were extremely happy with the results. And continue to breed best to best. If you truly liked what you had, you would also probably end up with a linebreeding program without even realizing it. Just my thoughts on it, but you probably already knew that.

Take care, Willie

[Trueblue]

I may be wrong about this but I believe that when scientific studies have been done on control groups in controlled environments to test the viability of "purging the genetic load" through sib to sib inbreeding,the majority of those control groups went extinct due to inbred depression and success in the minority was only measured by whether or not they could overcome inbred depression.I believe over all fitness and vigor were still questionable especially outside the controlled environment.I think that most of these studies are being done to try and map a way forward with endangered species in captivity where populations are very small and diversity is no longer an option.

[JTG]

Doing the same thing over and over and expecting a different result is one of the definitions of insanity. If you look at hounds over the last thirty years, not much progress. (There is a few exceptions.)
If you study other breeds of dogs mostly , service dogs they will mirror what I have been saying for some time now. Go ahead keep doing what you’re doing and keep getting what you’re getting.
Jtg-

[Trueblue]

If you study other breeds of dogs mostly , service dogs they will mirror what I have been saying for some time now. Go ahead keep doing what you’re doing and keep getting what you’re getting.
Jtg-

I would be interested in reading about these service dogs you speak of.Have they had success in purging their genetic load through inbreeding ? Could you post a link.But I would be more interested in the results you are getting especially since you are doing it with my breed of choice.Could you share with us the details of the success that you have had in your own program ?

[JTG]

True Blue, I posted litters of my pups before. You can look up Frankie the seeing eye dog and there's lots of information out there. You can also look at horses, chickens, cows and other livestock. Lots of money has been spent on these in respect to genetics.
Look what we are getting out there now--Slick treeing walkers and blue eye blueticks. As I said not much progress.

Jtg

[slowandeasy]

True blue,

The best thing that I could suggest to do. Is do all the research you can about guiding eyes for the blind. They are on the top of their game when it comes to reproducing. And I believe you will be surprised at their methods.

Take care, Willie

[Trueblue]

I guess I just need to be more direct.How come you make these pedantic posts about the superiority of your breeding program which you have to admit is controversial even among scientists,but you never are willing to share any of the documentation and details about your program.If you want us to follow your lead in your efforts to improve the Bluetick breed then share with us the fruit of your labor.I'm not talking about one picture of a litter of pups as evidence.Tell me you have more than that to offer in defense of your position ? Can you demonstrate to us that you have proven these theories to work in your own experience ? If you have truly made it work then lay it all out there,be open,be honest and be forthcoming with the trial and error you have had along the way.

[cobalt]

I admire that you stick to your guns, jtg, and I think you doing what you are doing is a great study in cause and effect of this method. I hope you've kept good notes and can publish your results at some point.
As a hobby breeder (very few litters), I am just an observer of the breeding circle, but am curious and stubborn about knowing the real, absolute truth. I know you feel that you are trying to help, but you must realize there are other valid theories and that your system doesn't hold water as of yet in many peoples minds. Maybe I play the devils advocate, but it is only to get you to validate your opinions. There are many questions you don't answer for whatever reason and nobody seems to defend you with testimony of your successes. It occurs to me that for the past 11 years of breeding the dogs of your choice (Cameron dogs), the dogs prior to them (50 years according to you), are not mentioned. Am I to assume they are still in existense, or not. You see, with the information supplied, you become your own worst enemy when trying to convince people you are the savior of our hounds.
As always, I wish you well in your endeavours and hope you keep posting your ideologies. It definitely enspires me to educate myself in areas where I am weak in knowledge.

[slowandeasy]

Guys,

This really shouldn't turn into a pissin match. Although I have advertised dogs in the past for a good chunk of years. I never was an advocate of blowing my own horn. Nor do I think JTG does.

However, I will give you another example. If you choose to need more living proof. There was another book written called wilderness patchwork author was Willet Randall. He secluded himself in the Adirondack Mountains. And bred Some of the best running beagles born. You will note if you read the book. There was probably never an outcross for over 20 years. There are numerous examples of success stories. But yes it is true that no one has 100% foolproof program. But it has become very obvious to me that there are more best to best breedings than people that follow a line breeding program. All I will ask, is if that is truly the way to go. Why is a made dog so expensive? And how come so many puppies don't turn out?

Again, it's not about one person thumping on their chest. I believe it's more about trying to get better results. I know I will keep on using what I have seen the best results from. And if I ever get it figured out to where I have all the answers. And can clone exactly what I want. I definitely will broaden my horizons to include the racehorse business. As there is literally millions to be made.

Take care, Willie

[JTG]

Willie, I just ordered the book, thank you for letting us know about it. JTG

[mondomuttruner]

Interesting subject!! I wish I knew more about some of the terminology but I try to follow. There's too many people breeding shit to shit just for the sake of free pups or worse yet, to sale.

[JTG]

Thank you for being honest, what a breath of fresh air. I will post some information. JTG

Interesting subject!! I wish I knew more about some of the terminology but I try to follow. There's too many people breeding shit to shit just for the sake of free pups or worse yet, to sale.