I watched a PBS Nova movie awhile back called Dogs and More Dogs and have been contemplating how to organize the hour of great information into blogs. What I have decided to do is write one or two blogs solely on the movie and then in one blog tie the movie in to the concept of the Russian feral dogs, and finally another blog that ties part of the movie into a part of the National Geographic article I have not talked about yet. The first part of the movie talked about the specifics of the evolution of dogs from wolves and how there is some controversy over how it exactly happened, which was news to me but not particularly surprising. The middle section of the movie took a closer look at a particular breed of dog, the Saluki, and went in to detail on some particular traits of the Saluki and how they might have evolved. Finally, the movie looked into the evolution of not only physical traits of dogs but the behavioral trait of dogs.
THE SALUKI
The Saluki is more of an unusual breed. It isn't a dog that you hear a lot of people owning as pets but it is considered the "Porsche" of dogs. It is one of the oldest known breeds of domesticated dog and was found in Egypt 1000s of years ago. These dogs started out as "sighthounds" and historically travelled with nomadic desert tribes to hunt.
Some of the main traits of this breed are its long legs, skinny waste, large heart and lungs, and its nose. Its long legs are a huge advantage when hunting and chasing something down in the open desert/field. These dogs can travel 10 feet in a single stride and all four of their feet are off the ground twice during one stride. The Saluki has such a skinny waste so the dog can easily tuck its legs high into its chest when running which allows it to travel farther and faster. The heart and lung in this variation of dog are oversized. This allows for more oxygen to be carried to, and waste to be carried away from, the muscles when this dog is running full speed. Even the nose is shaped and designed to help cool the blood.
In the video, a Saluki owner/breeder was interviewed and she said she wanted to breed the dog to have a longer neck and more muscle definition in the rear. This means she is more likely to try and breed her Saluki with another Saluki with those traits to try and come up with some longer necked and more defined offspring. But 1000s of years ago, when this breed of dog was evolving in Egypt, the Ancient Egyptian pharaohs did not know they were artificially selecting dogs with longer legs, skinnier wastes, or larger hearts and lungs. They were simply rewarding the dogs who did the best at whatever task they were asked to do. The fastest Salukis caught the most prey in the desert, those dogs were then in turn rewarded (usually with food) more than the dogs that were too slow to catch the prey (possibly because of their larger waster or shorter legs), the dogs that got fed more, lived longer and got to produce more offspring. Producing more offspring led to the passing on of their longer and leaner genes, and hence selection of those genes. To think that the Ancient Egyptians knew what they were doing is a little far fetched. They were simply rewarding the dogs that did the best, just like giving gold stars to first graders who do well on tests.
Artificial selection and dog breeding is more of a science today because we are trying to breed dogs for traits that they don't really need to use anymore. 1000s of years ago it was easier to breed for traits (although subconsciously) that produced faster dogs, but today wanting to breed for a more defined dog is going to be harder because the dogs today are not required to do any activity that requires more defined rear muscles, or a longer neck for that matter. It is going to be harder to see what dogs possess the traits for larger hearts and lungs because the Salukis today are not expected to run at top speeds for long periods of time anymore. Artificial selection started out as a means for dogs to be better at their jobs. Today it seems artificial selection seems to be a means to produce the prettiest, most aesthetically appeasing dog.
In one of the interviews in the movie, a dog researcher states that he fantasizes about a time when breeders breed dogs for behavior rather than looks. A day when dogs are bred to be the perfect companion and pet. I would have to agree with him. I love dogs and I think they are all (well most of them) are really cute but through breeding, particularly inbreeding, there are so many new genetic diseases and behavioral disorders that cause problems for pets and people think the only way to fix the problem is to get rid of the dog. If people would stop worrying about having the dog with the perkiest ears or curliest hair and focus on having the perfect life companion, it would be a win-win situation for everyone.
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