Hey silly sally. I am a forensic biotechnologist, I am continuing on to do more work in genetics to finish up as a geneticist. I do have an idea what I am talking about.
I have met some good arabs (see my post) and a the majority were actually the ones from endurance lines. LOL I love the thoroughbred, I LOVE LOVE the uber sensitive types. I own an andalusian arab cross who took 3 years under saddle before she would accept contact! I do know the type. I am talking about (mostly) the arabs I see around here, bred to be pretty but little else.
Think about this if you will...
You take a population of one breed of purebred dogs, say its 250 000 dogs. All these dogs are owned by breeders who breed 'to better the breed' by breeding for conformation, and will only breed the dogs that are excellent examples of the breed.
So each generation they throw out (by s/n) a minimum of 90% of the genetic material. They use the 10 to breed.
The next generation they throw out 90% again and so on and so on. How long do you think it takes before all the dogs in that population are so related that even if you out cross you are inbreeding?
Now you might say that doesn't matter you are breeding the 'best'. BUT you will find NEW and interesting health issues come up. A single random mutation can play havoc with what is left of the genetic profile of the dog. Just read up on "Impressive" in the AQHA and see the damage ONE stallion can do in a diverse population. Imagine if he was all through a breed before they found out what was going on (if everyone was breeding for looks and no one was breeding on performance)
Another issue I have with breeding for looks is that often its silly. For example take tollers. Tollers used to be able to have white on the back of their neck less than 10 years ago. Now according to their standard they can't. Now this doesn't affect their health, temperament, or working ability. But the really silly part is that its not even inheritable. The problem is that most breeders don't really understand medalian genetics and dogs are more complicated than pea plants. (tho its a great beginning)
Markings are NOT directly inheritable. Look at clones. Cloned animals have markings in different areas. It has to do with activation of genes within the womb. So toller breeders are throwing out genetic material for no reason!!
Actually I own a breed that is very inbred. BUT they are outcrossing like crazy now that the traits they want are there.
If you want a great example of what inbreeding can do. Look at the cheetah. They are so inbred as to practically be clones of eachother. They can accept skin grafts from 'unrelated' cheetahs.
Good article here http://www.messybeast.com/inbreed.htm
Now that is not to say 'some' inbreeding or line breeding isn't good. You acutally need s small amount of inbreeding to keep a population fit for its environment (or a dog breed to have a type) If anyone wants some 'light' reading google Sewall Wright or one migrant per generation rule (hahah) tho some are now saying you need 10 per generation to keep heterozygosity alive. http://www3.interscience.wiley.com/journal/119217980/abstract?CRETRY=1&SRETRY=0 If I remember correctly Wright thought that a 0.2 inbreeding co efficient was ideal. This is the gold standard used by animal conservationists around the globe.
Now if you look at people breeding for working ability you will see a much greater diversity in phenotype than you do in conformation dogs. Take Border Collies for example. The conformation version all look big and blocky (like aussies) with lots of hair. The working type varies in coat type, ear style and to a degree body style. There is a lot more genetic variation there, which leads to a more stable population when you can't breed outside your breed.
I could go on more.. but this is turning into a novel
I love to talk genetics and breeding.
I have met some good arabs (see my post) and a the majority were actually the ones from endurance lines. LOL I love the thoroughbred, I LOVE LOVE the uber sensitive types. I own an andalusian arab cross who took 3 years under saddle before she would accept contact! I do know the type. I am talking about (mostly) the arabs I see around here, bred to be pretty but little else.
Think about this if you will...
You take a population of one breed of purebred dogs, say its 250 000 dogs. All these dogs are owned by breeders who breed 'to better the breed' by breeding for conformation, and will only breed the dogs that are excellent examples of the breed.
So each generation they throw out (by s/n) a minimum of 90% of the genetic material. They use the 10 to breed.
The next generation they throw out 90% again and so on and so on. How long do you think it takes before all the dogs in that population are so related that even if you out cross you are inbreeding?
Now you might say that doesn't matter you are breeding the 'best'. BUT you will find NEW and interesting health issues come up. A single random mutation can play havoc with what is left of the genetic profile of the dog. Just read up on "Impressive" in the AQHA and see the damage ONE stallion can do in a diverse population. Imagine if he was all through a breed before they found out what was going on (if everyone was breeding for looks and no one was breeding on performance)
Another issue I have with breeding for looks is that often its silly. For example take tollers. Tollers used to be able to have white on the back of their neck less than 10 years ago. Now according to their standard they can't. Now this doesn't affect their health, temperament, or working ability. But the really silly part is that its not even inheritable. The problem is that most breeders don't really understand medalian genetics and dogs are more complicated than pea plants. (tho its a great beginning)
Markings are NOT directly inheritable. Look at clones. Cloned animals have markings in different areas. It has to do with activation of genes within the womb. So toller breeders are throwing out genetic material for no reason!!
Actually I own a breed that is very inbred. BUT they are outcrossing like crazy now that the traits they want are there.
If you want a great example of what inbreeding can do. Look at the cheetah. They are so inbred as to practically be clones of eachother. They can accept skin grafts from 'unrelated' cheetahs.
Good article here http://www.messybeast.com/inbreed.htm
Now that is not to say 'some' inbreeding or line breeding isn't good. You acutally need s small amount of inbreeding to keep a population fit for its environment (or a dog breed to have a type) If anyone wants some 'light' reading google Sewall Wright or one migrant per generation rule (hahah) tho some are now saying you need 10 per generation to keep heterozygosity alive. http://www3.interscience.wiley.com/journal/119217980/abstract?CRETRY=1&SRETRY=0 If I remember correctly Wright thought that a 0.2 inbreeding co efficient was ideal. This is the gold standard used by animal conservationists around the globe.
Now if you look at people breeding for working ability you will see a much greater diversity in phenotype than you do in conformation dogs. Take Border Collies for example. The conformation version all look big and blocky (like aussies) with lots of hair. The working type varies in coat type, ear style and to a degree body style. There is a lot more genetic variation there, which leads to a more stable population when you can't breed outside your breed.
I could go on more.. but this is turning into a novel
I love to talk genetics and breeding.
I do agree that there is an issue with breeding for looks. I really do wish that there was some sort of requirement for a dog to be proven some other way in order for them to be finished. In labs, for example, I would like a dog to have to pass some sort of hunt test and/or performance requirement and/or temperament test and have clean health screenings in order for them to be a CH. Honestly, if it doesn't like water, won't retrieve, is gun shy, has aggression issues towards dogs or people, is nervy, is not biddable, is not at all athletic, etc--who cares what it looks like? It is not a good example of what a lab needs to be
What I also have an issue with is the breeding for extremes that is damaging breeds. On one side you have confo lab breeders who SWEAR that the reason their dog appears alarmingly obese is that it's just so muscular (riiight--I've laid my hands on some of said dogs, and that is not muscle), and on the other side you have field trial breeders popping out dogs who have been bred to be so intense as to compete in field trials (which tend to be much more demanding than hunts--more like hunts on crack) that they do not even make good companions.
In addition, there are breeds that are not heavily divided into field and show lines, thus having a good deal of show dogs that are also performance dogs, that do have serious health issues. I heard recently that with Chesapeake Bay Retrievers 1 out of 4 dogs has hip dysplasia. In addition, flat coat retirevers have lots of problems with cancer.
However, this is an issue that dog people need to figure out how to solve together, rather than making it an us vs. them issue with confo breeders. I think this is where the documentary did a real disservice. By moralizing the issue of inbreeding rather than concentrating on the health aspects (asking the kennel club official if he would have a baby with his daughter was a cheap shot IMHO--dogs don't moralize like that), by making a clear attempt to draw a parallel between show dog breeders and Hitler, by referring to dog breeding as "playing G-d with dogs," they clouded the issue and put many people on the defensive, neither of which solves anything.
I think this needs to be less about "OMG--look at those horrible show breeder people!" and more about what the dog community as a whole can do to reverse this disturbing trend.
Do you think that performance breeders should start doing things like outcrossing, but not just in their breed but in similar breeds?