Tag Archives | Collies

Of math, fashion and wiffle hounds

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My oldest son has been struggling with freshman Biology, so the concept of evolution has been on my mind a lot lately. I have also been reminded that evolution applies, not just to organisms, but to points of view. Sometimes it can be easy to forget that you once held a different view – unless of course you are foolish enough to write it down for others to find later. I have been writing about horse color long enough now that I have had that happen!

The reminder of this came from my husband. Longtime readers of the blog have probably picked up on the fact that I have a strong interest in the issues surrounding genetic diversity. It is, as I have mentioned, one of the themes that runs through the upcoming books. My close friends could probably warn readers that it is a tempting soapbox for me, particularly when it comes to the topic of dogs. That was exactly what I was doing – standing on that soapbox – when my husband reminded me that I once held a very different point of view on the subject.

He has every reason to remember this, since there was a time when the topic came up often between us. My husband is a physicist working in the field of optics. When we first met, he was intrigued by the possibilities of using genetic algorithms to solve complex design problems. A genetic algorithm is a mathmatical tool that narrows down variables by “breeding” the possibilities until an optimal solution is found. He was experimenting with genetic algorthims, and I had recently bought my first Arabian mare after spending most of my teen years planning my future breeding program. I was more than happy to explain all the different inbreeding, linebreeding and outcrossing schemes breeders had developed over the years.


My husband used this diagram to illustrate a chapter on genetic algorithms in his book. My understanding of how he used the idea doesn’t go much deeper!

I was familiar with them because I had my heart set on breeding animals, most specifically Arabian horses and Rough Collies. Since I could not convince my parents of the pressing need to start populating our home with dogs, or to acquire land for horses, I used the time to learn all I could for the day when I could do those things. When the time came, I was determined to be the most informed breeder possible. I devoured issues of Arabian Horse World. It was the 1980s and  the market for Arabians was at its peak, so each issue brought countless images for a horse crazy girl trying to determine just what qualities she would emphasize in her hypothetical breeding program. While other girls were pouring over fashion magazines and beginning to notice boys, I was filling ring binders with notes on bloodlines and affixing sticky notes to the important pages. As you can see, many of them are still there today.

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I was smitten by pictures of the stallion *El Shaklan. The more something looked like an imaginary elven horse, the better. I was not an especially practical kid.

Arabians appealed to my artistic sensibilities. My interest in Collies came about in a more personal way. My grandfather was a Collie man, and encouraged me to read Albert Peyson Terhune’s books. Mr. Terhune had lived in the same town, and traveled in many of the same dog circles, as my grandfather’s family had when he was a boy. Like so many, I fell in love with the breed as it was portrayed in Mr. Terhune’s books. When my parents offered to give me my very own dog for my twelfth birthday, getting a Collie seemed a natural choice.

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My grandfather’s favorite Collie, Glengay Sandy Boy. The inscription on the back of his photo is the Terhune quote, “a thoroughbred in body and in soul.”

I knew the “proper” way to obtain a quality dog. My parents, however, had different ideas. I wanted the perfect bitch with which to start my grand breeding program. My parents wanted something within their price range and a reasonable driving distance. The result was the dog at the top of this post. She came from a local farmer who raised a few Collies on the side. She wasn’t the potential foundation female I would have liked to have gotten, but she was a dog of my very own. When you are twelve, that counts for a lot.

My grandfather, when he received her photos, was quite critical. She had a pronounced stop, which was not proper. The angles of her face were all wrong, and she carried her tail in something awful close to a curl. But the real deal-breaker was her prick ears. As soon as she left the puppy stage and those ears went up, he ceased to consider her a Collie. Purebred Collies had tipped ears. She was, he insisted, nothing more than a “Whiffle Hound.” She was no relative of his beloved childhood Collie, Sandy.

Looking back, perhaps that reaction planted the seeds of doubt about what was valued in the animal fancies. It was obvious to anyone familiar with the standard that Brandy was a Collie of inferior type. I would have readily admitted as much. She was, however, a wonderful companion for a young girl. I thought she hung the moon, and her over-large, erect ears seemed like such a little thing in comparison to all that was great about her. We competed in obedience for much of her youth and mine, and it was pretty clear which of us did the better job. (Her ears were less of a limiter than my tendency to confuse left and right.)


Pictures of my grandfather with his ‘thoroughbred’ Collie, Sandy, and me with my ‘wiffle hound’, Brandy. Interestingly enough, we are the same age in these photos and adopting quite similar poses as we encouraged our dogs to do tricks for the camera.

But when Brandy passed away at fifteen years of age, I was explaining close linebreeding (the word I used at the time) to my husband. I had absorbed those ideas from the cultures that surrounded Arabians and Collies, and if anything was going to marinate a young animal lover in the twin concepts of “blood purity” and the usefulness of inbreeding, it would be the world of those two breeds.

But something happened along the way. Soon after we married, my husband’s work took us away from our small farm in Alabama, and to city life here in Charlotte.  I had already begun to question the consuming nature of raising dogs and horses, having seen that more closely through the experience of a number of friends. My interest in breeding animals became more academic, and less about laying the foundation for future activities. My mindset shifted from future breeder to a person who would own a series of beloved family companions, and who just happened to be very interested in the topic of genetics and breeding.

It was the academic interest in animal breeding that exposed me to a new way of thinking about breeding programs. My interest in color motivated me to read journal articles. Many of the authors of those articles also wrote about breed conservation and genetic diversity. Over time, the ideas presented in those papers brought about an evolution in my thinking. Like classical evolution, the change was gradual – a shifted position here, and new insight there, until something quite different took the place of what had been before.

Thankfully for me, this process occurred in the peace and isolation of my own research. I could think about the issues involved in a fairly objective, unemotional manner because no one was clamoring for me to reach a specific conclusion. Now many of those issues have become a source of controversy and bitter battles within the animal fancies. This has played out most visibly in the British dog show world, which was rocked three years ago by the documentary Pedigree Dogs Exposed. That program brought genetic diversity out of the realm of academic papers and into the public square. It is pretty safe to say that unemotional is not a feature of the situation!

In this reaction, many have called the focus on genetic diversity a passing fashion. That is not surprising, since fashion has long driven animal fancies. That is a natural frame for viewing motivations behind breeding decisions. I do believe, however, that calling the subject a fashion does a disservice to kind of thought that goes into breeding decisions. The acceptable angles of a Collie head, and the proper carriage of their ears, is a fashion. The acceptable amount of white on the legs and face on a horse are a fashion. The benefits and hazards of an increasingly homozygous population is a much larger issue. The truth is that breeders are dealing with competing concerns, with uniformity and predictibility being the very essence of selective breeding, and with its opposite, heterogenity, being so closely tied to health. That is not fashion: that is about the limits of the system as it really is. It is essential to understand those trade-offs if breeders are to make good decisions.

As I have said, the Equine Tapestry books touch on the subject of genetic diversity. Because the way a registry defines “breed” and “purity” has a huge impact on colors – both what is ruled in and what is ruled out – it is quite relevant. It is also true that misconceptions about purity and breed integrity have big implications for animal coloring. Because color is so easy to see, and is often the result of far more straight-forward inheritance than things like conformation or breed type, it tends to be on the front line of selective pressures. But beyond those issues, it is my hope that the books will raise questions about how we integrate our growing understanding of genetics into real world breeding decisions.

I have a few more posts to make that expand on some of these ideas, since I want to bring some of these ideas back to issues that touch more directly on color. I also plan to add another page (much like the Splashed White Project page) to the blog with a collection of links for further reading on genetic diversity. Perhaps they can plant the seeds for a more rational dialogue on the topic.

Twenty years ago, when I talked to my husband about linebreeding, I never mentioned genetic diversity. It was not a concept that had come up in my reading at that point. Today when I pulled the copy of my husband’s book, thinking I might find some of the images that came from his work in genetic algorithms, I found the following passage:

We intuitively know that larger populations will bring greater diversity and better sample the solution space. If the ranking function is nearly flat, poor attributes will stay in the population longer. If the ranking function is steep, the population swiftly becomes inbred. A lot of mutation can slow the convergence, while no mutation will lead to premature stagnation through inbreeding.

That passage pretty much sums up the situation facing breeders. If the selection process (what he calls a ‘ranking function’) is minimal, we will get a mix of good and bad attributes and not a lot of control over which we get from any particular breeding. That is the part I knew. At the other end, if we use extremely strict selection, we run the risk of a dead end where the variables present are too limited to provide the answer to a problem. For many, my younger self included, that is the missing piece. I may not have understood then, but the math certainly gave my husband a more complete picture. It almost makes me wish I hadn’t spent so much of my high school algebra classes doodling horses in the margins of my notebook.

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Merles and unrelated eye defects

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In the previous post, defects in the eyes were used to help identify a homozygous merle. That is often a strong indicator, but there is one situation where that is not always helpful. Collies, and some of the closely related breeds, have a number of issues with their eyes that are unrelated to the merle gene. Compare the normal eyes of the merle Shetland Sheepdog, above, to the eyes on the merle Rough Collie below.

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Like the Great Dane in the previous post, this dog has an eye that appears to be too small and set incorrectly. Her left eye, which is blue, also has a distorted pupil similar to the one seen on the Dane. It is more obvious when viewed from the front.

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Although it might look like she is looking to the side in this shot, her pupil actually skewed over toward that corner, giving her a cross-eyed look.

She is not a double-merle. Her pattern is typical for a single merle with moderate white irish patterning. Whatever is wrong with her eyes, it is probably separate from her merle coloring. Her one blue eye makes the problem more noticeable, but chances are she would have had issues whatever color she happened to be.

And that is why distortions in the eyes on collie breeds are not necessarily proof that the dog is homozygous for merle. Fortunately for identification purposes, most double-merle Collies are quite dramatically white so they are unlikely to be mistaken for a heterozygous merle.

But dogs like this one also point to the reason why using double-merles in Collie breeding programs is a bad idea, even when someone else made the ethical compromises necessary to create the dog in the first place. Because two copies of the merle mutation damages the eyes, there is no way to know if a homozygous merle breeding animal had eye problems unrelated to the merle coloring. Dismissing eye problems with the assumption that the heterozygous offspring will not be affected could be a mistake, because there is no way to be sure that the homozygous parent has otherwise normal eyes.

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Merle and black pigment

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As I mentioned in a previous post, I was fortunate enough to get some wonderful comparison shots while I was in Kentucky. It seems a good time to share this one since I touched on the topic of merle in dogs in the last few posts. This is Lily, a sable merle Collie. Here she is with her ordinary sable companion.

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As I had mentioned in a previous post about merle in dogs, the merle gene effects black pigment. This is why the sabled areas on head are muted on Lily compared to her friend. With only a small amount of black pigment present, the effect is pretty subtle. From a distance Lily looks a little washed out and pale. Her blue eye is quite a giveaway for the merle gene, since those happen even with merles that are completely red pigmented. Her ears, which are often the blackest area on a sable Collie, are the other giveaway.

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Her other ear and the colored area along her back skull are all visibly merled.

I should also clarify that she is what Collie breeders call a color-headed white with a single merle gene. She is extensively white because she is homozygous for the color-headed gene, and not because she has two copies of the merle gene.

Here is a typical (non-merle) color-headed Collie. (Photo from Wikimedia.)

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Unlike double merles – and the white Boxers in the previous post – the gene responsible for this pattern usually leaves the head, nose and ears dark.

Here is my friend Andrea Caudill’s merle Cocker Spaniel, Domino. (Thank you, Andrea, for letting me use pictures of your sweet boy!)

Domino

Domino is probably a double merle. Although many double merles are very white, especially on the face, some carry enough color that they could be mistaken for a dog that had a single merle gene and one of the more extensive piebald patterns.

Since posting about the fact that merle acts on black pigment, several people contacted me about red dogs that were merle. In some breeds, red is used to describe liver, which is a form of black pigment. The people writing were not talking about liver red. In these cases, what was meant was truly red (or yellow) pigment. Some of the dogs did in fact look red, or had what looked like merling in their red-pigmented areas as well as their black. It was often less extensive, but still it was enough to make me wonder how absolute the connection was to black pigment.

If you look closely at Lily (the images link to larger pictures), the area at the corner of her blue eye, running towards the blaze, is roaned. Here is a sable Dachshund with an even more merling in the red areas of his face. (For comparison, here is a sable Dachshund puppy with the merling mostly confined to his sable areas.)

It is also true that merle, when paired with the harlequin (Harl), will effect red pigment. In Danes these dogs are called fawnequins. (Image from Wikimedia.)

Fawnequin

The harlequin gene has much the same effect on brindles that inherit the merle gene, which are known as brindlequins. Compare that to a more typical brindle merle here, where the red/yellow pigment is not especially altered.

So it appears that the link between merle and black is not absolute. I know I’ll be looking at merles with red pigment more closely in the future. I am curious to see how common this is, and why it happens in some red dogs but not most.

(I promise to return to horse colors with the next post, which will have the Dominant White stallion Sato!)

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