One of my favorite activities is spending the day at a horse show with my camera. I started going to shows because I needed examples of the different colors and patterns for articles and presentations. The equestrian community has always been generous with their knowledge and their animals. Their willingness to set up their horses (and tolerate me when I get underfoot) has allowed me to take more than 50,000 photos.
There was a time when I favored shows where pinto or appaloosa horses were sure to be present. I carried a mental checklist of things I hoped to find, eager to fill the gaps in my library of images. The average number of pictures I took at an event showed my selective approach. Ten years ago, I might come home with a hundred shots from a Paint Horse show. Today that number is typically in the thousands, no matter what type of show.
So what changed? The difference is that I stopped thinking of some horses as ordinary, and stopped mentally dividing colors into “interesting” and “not so much.” Somewhere along the way, I stopped thinking in terms of “red is red.”
That’s the phrase that sums up my earliest approach to horse color. You don’t need to spend much time in places where horse color is discussed to hear that mantra. Red is red. Yes, your blonde sorrel is red. Your liver chestnut? Just red. I know why it was once important to say this. There was a time when it was necessary to tell someone that there wasn’t a special “Arabian chestnut” that was different from “Quarter Horse chestnut” or “Belgian chestnut.” Today, though, the level of understanding is much different.
In light of that, I have come to question the value of stressing that a horse is “just chestnut” – or “just” anything. It sounds final as if there is nothing more to say on the subject. It suggests that there are no more questions.
But even when it comes to “red” horses, there are unanswered questions.
The two horses in the image at the top of this post are both chestnut. If tested, their results would be the same. That is the same Haflinger in the second image, next to a palomino Quarter Horse. Unlike the first pair, the average person would have a difficult time telling those two (genetically separate) colors apart. The difference between the non-mealy areas of the Haflinger and the body color of the palomino is subtle.
With current testing, all three horses pictured below would have the same test results: e/e at Extension (MC1R). Visually, they are different enough that even someone unfamiliar with horses could tell them apart. The logical question, then, is what other factors influence the final color? What makes those three horses so different? Clearly, the alleles at Extension do not tell the whole story.
The limitations of testing apply to other colors as well. At the moment, it is only possible to test for recessive black (a) at Agouti. In the absence of the mutation for black (a), the result is the default (A), bay. The test cannot distinguish between bay and the two other black-pointed phenotypes: brown and wild bay. Again, is that the whole story?
These are interesting questions. It is important to note that they are also scientific questions. The terms used for variations in shade are subjective, but the reasons for the differences are valid areas of inquiry. There have been past studies looking at the inheritance of liver chestnut and of flaxen. There have been recent studies on the synergistic relationship between Extension and Agouti and its influence of shade, and even a potential lead on the mealy (pangare) pattern. Researchers are looking at these questions. But even if that was not the case, there is something to be said for seeing “ordinary” colors with a sense of wonder. Wonder is one of the most powerful tools in science. Wonder generates questions, which is the first step in scientific research.
Up until now, most of the posts have dealt with white spotting. That has been the focus of existing research and numerous discoveries. That will not always be the case on the blog. I ask a lot of speculative questions and wonder about many aspects of horse color. Most of those won’t have tests, and some may not even have been addressed by formal studies. But I wanted Equine Tapestry to “pull back the curtain” a bit when it came to research, and questions are where that starts.