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Discussion Starter #1 (Edited)
For the gene nerds, this one is also interesting. It's about poodles.

http://www.cgejournal.org/content/2/1/14

Conclusion:

We demonstrated that the incidence of both Addison’s disease and sebaceous adenitis in Standard Poodles increased as a result of an artificial genetic bottleneck involving a small group of show-winning founders from the mid-twentieth century. This bottleneck led to inbreeding over two decades with the results that 50–60 % of an average Standard Poodles ancestry can be traced to a few lines. We conclude that a number of ancestral traits associated with autoimmunity, some common to both SA and AD and some unique to each, were concentrated by inadvertent positive selection during close linebreeding for show winning form.
If you want to really get into some reading here's all the studies: http://www.cgejournal.org/content
 

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They need to open the books on every breed.
Yup, but that ain't gonna happen. Not in the current system and not under the rules of the current registries. I wish there was some kind of registry that had a permanent open stud book for every breed. Like with koolies (I believe) where they have an A/B/C category thing going on. Can't remember the exact details, but it was something like this:
Category A: purebred
Category B: mixed (offspring of purebred x other)
Category C: lookalike (undetermined heritage)
You can breed all categories together and after a couple generations any dog can become classified as category A, with the motto 'if it looks like a frog, acts like a frog, sounds like a frog, we'll consider it a frog'.

This way you can always get fresh blood in a population with minimal hassle.
 

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Discussion Starter #5
I am just glad there is actual research going on about these things. Maybe that will lead to some changes further down the road.

I love the grade system the koolie registry has.
 

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I think people are starting to realize more and more how big of an issue genetic bottlenecks are. It's not enough to just stop inbreeding now, if the dogs all come from 4 founders only 50 years ago. A ton of breeds from Europe went into sharp decline during the world wars when people had to put down the dogs in their kennels because there wasn't enough food. Some breeds were basically extinct and bred back from a few individuals, or were recreated from scratch (and not in a responsible, well thought out way).

I'd really like to find out more about what conservationists know about genetics in small populations. When you only have so many rhinos or something, it's not like you can outcross to elephants. So what do you do? There is a lot of info out there but the dog community doesn't realize yet that many breeds have such small effective populations that they might as well be pandas or black rhinos.
 

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Yup. Just had a discussion... oh what am I saying. A rant. On the Dutch dogforums I'm on where someone asked "Is it OK if I breed my dog to his sister? His breeder said it was OK and happens all the time in his breed." His breed meaning American bully. And some American bully people on there reply 'inbreeding is totally OK if done responsibly'.
I went nuts.
 

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Discussion Starter #8 (Edited)
Is there a species we have brought back from that tiny of a population.

I do see some good coming out of this. I see dog people who were vehemently against PDE that now espouse some of what they say. But I also hear of people saying these topics are not gettin discussed even now with science and studies. That is frustrating.
 

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Yup. Just had a discussion... oh what am I saying. A rant. On the Dutch dogforums I'm on where someone asked "Is it OK if I breed my dog to his sister? His breeder said it was OK and happens all the time in his breed." His breed meaning American bully. And some American bully people on there comment 'inbreeding is totally OK if done responsibly'.
I went nuts.
"Responsibly" to some people seems to mean "ok, I thought about it for a minute and decided to do it. At least I was responsible and thought about it first" *head desk*
 

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Is there a specie we have brought back from that tiny of a population.

I do see some good coming out of this. I see dog people who were vehemently against PDE that now espouse some of what they say. But I also hear of people saying these topics are not gettin discussed even now with science and studies. That is frustrating.
I believe it's been done. Sometimes with outcrossing to other populations which could be similar to crossing a dog population in Europe with that in the US (for some breeds that's a hard split). Or crossing a working dog with a show or performance bred dog. There were some pumas in Florida who were extremely inbred to the point of deformities, but they were able to open a path for those pumas to mingle with other pumas to the north (apparently highways and things cut off the one population) and it was brought back.

I don't know if anybody has brought back such a tiny population to genetic viability without the ability to outcross. I think there are ways to do it much better than we're doing now.
 

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European bison were down to 12 in the early 1900s. But they're having fertility problems now so that obviously was too few. American bison were down to 750 in the 1890s, they seem to be OK now. Syrian hamsters are almost all descended from one litter someone found in the 1930s, they aren't super healthy but don't seem to have fertility problems anyway. Elephant seals were down to 30 at one point, but tend to have weird birth defects. (I just Googled "examples of genetic bottlenecks" :p)
 

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I don't remember where I read this, so take it with a grain of salt, but apparently you can save a bottleneck sometimes if you have different populations to cross. If one line went one direction and the other went a different way, they will have different mutations and different genes after 50 years apart. It may not get rid of a some diseases that they still have in common, but it can help the more generic causes of inbreeding depression. So it doesn't even need to be an outcross to a different breed to get some use out of it. But some people are as obsessive about their lines and not outcrossing those as others are about breed purity. You *can* breed any BCs together, but there are a lot of purists who wouldn't.
 

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Discussion Starter #13 (Edited)
I have so many ideas on how to implement something that would allow more outcrossing but I am not sure it is possible in the current environment. I would just like to see it be a viable option for breeders to use. Right now breeders virtually have no choice because of the way the system is set up.

Here's another interesting study: http://www.cgejournal.org/content/2/1/9

Results
For aortic stenosis, GDV, early onset cataracts, dilated cardiomyopathy, elbow dysplasia, epilepsy, and portosystemic shunt, most purebred groups were not statistically distinct from the mixed-breed population with higher prevalence in purebreds restricted to distinct subsets of purebred dogs. The conditions of atopy/allergic dermatitis, hypothyroidism, and IVDD were more pervasive across the purebred population with many groups having higher prevalence than the mixed-breed population. The prevalence of IVDD in purebred terrier groups was statistically lower than that observed for mixed-breed dogs.

Conclusions
The results offer an assessment of the distribution of inherited disorders within purebred dogs and illustrate how mixed-breed and subpopulations of purebred dogs do not differ statistically in prevalence for certain disorders. Some disorders appear linked to common ancestors providing insight into disease allele origin whereas others may be due to selection for common structural morphology. Knowledge of the origin of a condition may aid in reducing its prevalence in the dog population as a whole.
This table in particular:

http://www.cgejournal.org/content/2/1/9/table/T3
 

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I think people are starting to realize more and more how big of an issue genetic bottlenecks are. It's not enough to just stop inbreeding now, if the dogs all come from 4 founders only 50 years ago. A ton of breeds from Europe went into sharp decline during the world wars when people had to put down the dogs in their kennels because there wasn't enough food. Some breeds were basically extinct and bred back from a few individuals, or were recreated from scratch (and not in a responsible, well thought out way).

I'd really like to find out more about what conservationists know about genetics in small populations. When you only have so many rhinos or something, it's not like you can outcross to elephants. So what do you do? There is a lot of info out there but the dog community doesn't realize yet that many breeds have such small effective populations that they might as well be pandas or black rhinos.
I have read some of the conservation literature. It's complicated. The grey fox population (subspecies) on the Channel Islands of Santa Barbara CA was devastated by parvo back in the 1970s. If I remember right, the Santa Catalina population is thought to have been brought down to six individuals. However, recent studies have indicated healthy genetics. The explanation given is 'balancing selection'. Likewise, I haven't heard much talk of the California Condor, after being moved away from the brink of extinction, confronting serious genetic problems. For that matter, the folks talking about resurrecting the Tasmanian tiger or wooly mammoth from DNA don't much talk about minimum population size (MPS). On the other hand, there is little question that inbreeding has really messed up the Isle Royale wolf population.
Free-breeding wild populations subject to natural selection, however, are fundamentally different from captive animals whose mates are chosen by human breeders, and who are subject to show ring selection rather than natural selection.

With respect the OP . . . we need a lot more studies like this one . . . and a lot more research like that of Anderson and the Standard Poodle Project. . . which forms the backdrop for the poodle study.
 

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Discussion Starter #16
MastiffGuy, can you elaborate on that? I don't have time really to re-read everything and find where it says the time of most outcrossing was...

I have read some of the conservation literature. It's complicated. The grey fox population (subspecies) on the Channel Islands of Santa Barbara CA was devastated by parvo back in the 1970s. If I remember right, the Santa Catalina population is thought to have been brought down to six individuals. However, recent studies have indicated healthy genetics. The explanation given is 'balancing selection'. Likewise, I haven't heard much talk of the California Condor, after being moved away from the brink of extinction, confronting serious genetic problems. For that matter, the folks talking about resurrecting the Tasmanian tiger or wooly mammoth from DNA don't much talk about minimum population size (MPS). On the other hand, there is little question that inbreeding has really messed up the Isle Royale wolf population.
Free-breeding wild populations subject to natural selection, however, are fundamentally different from captive animals whose mates are chosen by human breeders, and who are subject to show ring selection rather than natural selection.

With respect the OP . . . we need a lot more studies like this one . . . and a lot more research like that of Anderson and the Standard Poodle Project. . . which forms the backdrop for the poodle study.
Agreed completely. I would love to see this across more breeds. Hopefully we will start seeing more studies out there!
 

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One way to get around the closed registry problem is to change registries. I've long been contemptuous of the Continental KC because they will register a dog or bitch without full pedigree history, and bring many BYB dogs back into a registry. They aren't real big on health tests (but the AKC isn't all that wonderful on that score either). But on the other hand, if you outcross/backcross there's a good chance you can register your dogs with the CKC or other secondary registries (depending on breed) so long as they preserve essential characteristics of the breed you claim them to be.
 

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MastiffGuy, can you elaborate on that? I don't have time really to re-read everything and find where it says the time of most outcrossing was...



Agreed completely. I would love to see this across more breeds. Hopefully we will start seeing more studies out there!
PM'ed you rather than taking away from your post.
 

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On every breed! Really?
Yes? Closed gene pools and strong selection (based on the breed standard among other things) and the consequences of that are not limited to a handful of breeds. It's going on in all breeds. The very definition of purebred, breed purity, is the cause of all the problems. That's genetics, a thing we humans can not fully comprehend yet, let alone control. A genetic bottleneck is a universal thing that happens when you take a couple individuals, breed them and all their offspring together and call it a breed, henceforth to be kept pure.
 
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