Watched a great program called "The Science of Dogs" on TVO last night. Based on findings from NA research, incl Univ of PA, it showed that the dog is the only mammal known to have such a "slippery genome": The genome naturally has recurrent tandem repeats in it. This means that changes in the physical characteristics of the dog, as an expression of changes in these tandem repeats, are more likely to occur. It is possible to start with a wild/domestic hybrid and within 25 generations to have created a new breed: This was the case of the Russian Aeroflot Sulimov dogs bred from a jackal hybrid for explosives detection.

The development of many breed standards emanates mostly from the Victorian age when the creation of the middle classes created a demand for what was then, effectively, "designer" dogs!

Recently I came across a print of a Dalmatian dating back to 1790. I was astounded at how much it looked like a hyena; primal looking, more flecked spots than round spots and not so pure white on the coat. Now I see that this is entirely possible to have been an early Dal version! (Incidentally it is the creation of the white coat in the Dal that is linked to some of the genetic problems Dals have.)

The downside to the slippery genome of dogs is that approx. 1 in 4 purebred dogs in NA are estimated to have some kind of genetic disease.

If you get a chance to see this program, I can highly recommend it!

It's been a while, but I do remember watching that program and I found it very interesting. I am sort of a science geek. As I recall, it was discussed that canis lupus familiaris is the only species known to have so much variety in outward appearance. After all, it is hard to understand how, for example, a Mastiff, a Whippet, and a Yorkshire Terrier can really be the same species!

I agree with Lisabet. If you get a chance to see the program, it's well worth it.