Wednesday, July 1, 2020

Where did all the German Shepherd genes come from?


Almost every “village dog” shows a trace of German Shepherd in its DNA. A range of other “breeds” also show up infrequently including Saluki, Basenji, Doberman Pinscher, Pomeranian, Boxer, Collie, Harrier, Labrador Retriever, Dalmatian,  and others. Considering that all of todays human established breeds originally come from the early natural dogs or by mixing other breeds to get a type wanted it is not surprising to find some shared DNA and the more pariahs that are tested the more are likely to be found. Some also have the same haplogroups and haplotypes  that are found in some “pedigree Canaan dogs”. It would be surprising if that was not the case since the Canaan breed is simply a small group, or family, established by taking in some 30 of these pariahs and breeding them for sale then excluding the rest. “The “breed” can be distinguished in much the same way as a human family that has bred in a closed community could be identified from other humans in the same geographic area. Most dogs in todays breeds are as closely related as second cousins. It is rare to find a dog with no genetic structure linking it to other breeds.

When “pedigree” dogs or unknown dogs that turn out to fit the genetic profile of the “pure” breed are tested then any trace breed found does not get reported. When a new “pariah” is added to the “Canaan breed” kennel clubs only require that the offspring breed true for 3 generations with existing registered dogs. That is equivalent to going back as far as great grandparents, each of  which would show up as 12.5% of the dogs genetic makeup. Once a new pariah is introduced to the breeding program and its offspring “breed true” to and is registered and its DNA added to the breed profile then all the related dogs will of course also test as being “pure Canaan”. If the relative finder on Embark tested 100% pure Canaan dogs is used GSD’s do show up as here:
So how do we explain the presence of this connection.
From Grace Gartel: “Since we first started testing dogs at Embark (and even before then, during our village dog research), the Embark team noticed that most village dogs across the globe share some German Shepherd Dog DNA (when it is less than 5% of their DNA, they are a "trace breed"). To be honest, we're not yet sure exactly why this is, but it definitely is a real biological phenomenon and has been noted by other labs (see for example https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5492993/).
The average amount of relatedness varies across the globe, and the exact amount varies between village dogs from the same region. This could relate to German Shepherd Dogs traveling around the world in the World Wars and other times, but we are not certain of that at this time. As we work to understand village dog genetics and history better, we hope to unravel this mystery!”
The suggestion that GSD’s were introduced by military into the area seems unlikely to explain this. Many other dog breeds have also been introduced and there is no reason to believe GSD’s could have bred so widely with pariahs worldwide that close to all pariahs even in remote areas now have some GSD in them. A more likely explanation would be that it is simply a continuation of genetic strains dating back to ancient times and has remained as a stable pattern. 


4 of 67 village dogs from this region had a trace of Gray wolf in their genetic makeup, 2 from Israel, 1 from Jordan and 1 from Kuwait. No doubt there are others not tested and again this is further evidence of the ancient origin of our desert dogs.
Some potential genetic health issues have been found in pariahs. Apart from the more common degenerative myelopathy (DM), which has become a major issue in the pedigree breed due to inbreeding, others already spotted in lower numbers in the pariahs include von Willebrands type II , factor VII deficiency (a blood clotting deficiency) and “Collie eye” Without fully testing any new pariah intended to be added to the breed BEFORE using them breeders could well be creating future problems. Thousands of desert dog pariahs still survive but, sadly, efforts to eliminate them by “rescuing” them or by Trap Neuter and Release (TNR) or worse,  to shoot or poison them if “successful” could lead to the end of these natural dogs while we still have much to learn from them.