Row B: Sprint dogs. Row C: Distance or Endurance sled dogs.
Chris has a very good post up at BorderWars.
It highlights a false claim that is often promoted in border collie circles: That border collies are bred just like Alaskan huskies. They just breed them for performance, pedigree doesn’t matter.
The Alaskan husky is what Chris calls an “ad hoc” breed. It’s really a type of dog that has developed for sled dog racing, and in order to do so, the sled dog racers have crossed in different things.
There are two types of racer with sled dogs, and both have different strains and breeding systems. Endurance races require dogs with a lot more Siberian husky, malamute, and even Anatolian shepherd ancestry, while sprint races incorporate things like pointer or saluki bloodlines.
According to the 2010 study Chris quotes, sprint sled dogs are much more outcrossed than the endurance dog, but both are more genetically diverse than purebred dogs, including border collies.
Chris goes on to quote a member of the American Border Collie Association who claims that the only difference between border collies and Alaskan huskies in how they are bred is that border collies have a registry.
Border Collies aren’t like either of the Sled Dog sub-populations. Even though the Distance [endurance]dogs have higher F(IS) values, they are still highly heterozygous and have a greater abundance of allele diversity. In other words, Distance dogs are being pushed genetically towards homozygosity faster than the Border Collie is being pushed, but the Distance dogs are starting from a more diverse and less inbred position.
The Sprint dogs not only have a greater abundance of allele diversity and a greater level of Observed Heterozygosity, they are also being actively and continually outcrossed. This simply isn’t the case with Border Collies.
Border Collies have a virtually closed breeding pool of dogs that go back to a few hundred founding dogs a century ago. Their effective gene pool is now equivalent to the genome of only 8 dogs. The number and impact of new blood (typically in the form of Registration on Merit) is negligible. The contribution of other breeds (like Kelpie and Bearded Collie) is highly limited, mostly ancient (a century ago), and not ongoing. The last documented non-Border Collie to enter the gene pool is almost 30 years ago with one Bearded Collie (Turnbull’s Blue) ROM’d within the ISDS.
The last time a Husky was improved with fresh blood was probably yesterday.
The truth is border collies are more like performance-bred bird dogs.
A fairer comparison is that border collies are more like Llewellin setters.
A Llewellin setter, for those of you not in North America, is a setter that is bred solely for hunting and trial work.
There is some debate in dog circles about whether to call these dogs a strain of English setter or to call them their own distinct breed.
They are much smaller than typical show strain English setters, though they do derive from that stock.
They have been bred solely for performance for decade after decade. They are very good at what they do.
But their registry is closed. I don’t think there is any significant gene flow between Llewellins and other English setters, though I could be wrong.
Llewellins are a working dog, but they are being bred just like any other purebred. It’s just they are being selected for performance only.
And that’s exactly what’s going on with border collies.
If border collies were that much like Alaskan huskies, you’d see extreme type divergence . Honestly, in border collies, you see about as much variation as one sees in Labrador retrievers. There are big ones and little ones, but they are all variations on the same theme.
What I find interesting about Llewellins and border colies is how hard it is to find out about what health problems exist in both breeds.
Google doesn’t help– and is contradictory.
The truth is that in both of these performance breeds there is a culture that just assumes the dogs are fine because they are worked, but compared to fancy breeds, there isn’t as much of desire or effort to find out what health problems actually exist.
And one way to deny it is to say that border collies are just like Alaskan huskies, then provide no evidence.
The truth is that whenever any organism with an evolutionary history of low inbreeding tolerance is bred in system that rewards greater homozygosity and tighter gene pools, health problems are just that much more likely to occur.
It matters not that the animals are worked and trialed and that people write romantic novels about them.
Performance bred dogs that are in these sorts of registries are ultimately in the same boat as the show dogs.
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