|The First Dog by Benjamin Cheever|
The Empty Nest
Dogs move in packs. Each time dogs broke away from the original family and moved on to better opportunities, they would mate with close cousins who'd migrated with them. Their offspring would have had less genetic diversity than their ancestors' because the parents were more closely related. As this process continued over thousands of years, diversity was reduced.
Humans, by applying artificial selection, have created smaller and smaller populations. If it's a very small population, it's called a bottle neck. In the case of dog breeds, the least amount of diversity will be a breed that's gone through the narrowest bottle neck.
The Norwegian Lundehund is a good (but unfortunate) example.
The ancestors of the Lundehund were not a breed per se, but rather a landrace, a local variety of domesticated animal that developed largely by natural processes. Their natural environment included rocky surfaces, craggy cliffs and steep fjords. For thousands of years the Lundehund was a genetically diverse balanced population.
The dog in its natural environment.
About a hundred years ago, the landrace was artificially "perfected" to negotiate rocky cliffs to hunt Puffin birds, now an endangered species. Some breed diversity was lost.
|The Hapsburgs had many genetic problems.|
Hemophilia was probably the worst.
The Lundehund suffers from a life threatening digestive disorder (Lundehund gastroenteropathy) that causes the dog to be unable to absorb protein and nutrients from food. Not all dogs are afflicted, but all Lundehunds are carriers. Although the disease can be managed, there is no cure. The average age of death is 7-8 years.
The unique feature of the Lundehund is it's polydactyle foot with fully formed, jointed and muscled toes. Note the six toes instead of the normal four. I wonder if she can open the refrigerator door.
In addition, the dog has extreme range of motion in its shoulders, neck and ears. (The ear canal opening can be controlled by ear movement). These distinctive traits, found only in the Lundehund, likely developed from natural pressures the dogs experienced thousands of years ago. If breeders were to cross the Lundehund with another breed to increase diversity and reduce the incidence of disease, these extraordinary features would be lost forever. Breeders face difficult decisions.
To read more about the unusual Norwegian Lundehund, click here