WE MENTION GENETIC DIVERSITY frequently on this website. I believe it is an important issue for working dogs generally, particularly for sleddogs and specifically for Seppalas. Let's define it. Genetic diversity means that the genome (the total array of genes held by a species or breed) is rich in alternatives. It means that many gene loci have a series of different alleles (alternative forms of a gene that "lives" at a particular site or locus, all controlling the same trait or traits but producing different effects in that trait). Therefore it also means that relatively few loci are always homozygous (having just one form of the gene rather than two) due to an absence of alternative forms. The science of population genetics tells us that genetic diversity is important to the survival of a species.
NATURE USES GENETIC DIVERSITY to produce an ever-changing array of slightly different forms of the same species. In this way, the species is able to respond to change and to environmental challenges, through the action of natural selection. If one organism fails to survive a new virus, then perhaps another one will because it is different in some slight way that gives it an advantage. A species that lacks genetic diversity lacks the potential to survive, if the conditions of its environment change markedly. The cheetah is one example of such a species -- marked for near-term extinction.
THE CHEETAH LACKS DIVERSITY because it has suffered from genetic bottleneck events, in which its breeding population was cut back to a few individuals, from which the species re-populated. This happens regularly in purebred dogs; it has happened repeatedly to Seppalas. People speak of the "Markovo bottleneck" (though actually it is the post-McFaul bottleneck, since Markovo did not create the bottleneck event but tried to alleviate it); but there have been more such events than just the one. The importation of Siberians to Alaska was one -- relatively few individuals were selected out of a vast pan-Siberian tribal reserve. When the Siberian moved out of Alaska to the "lower forty-eight," that was another bottleneck event. Registration of the Siberian Husky in 1930 (AKC) and 1939 (CKC) was another bottleneck that was perhaps more severe than the post-McFaul event. The post-Markovo period, in which out of all the young stock produced by the Bragg/Bush, Egelston, and Prado breeding, only a handful passed on their genes, caused yet another bottleneck, which may quite fairly be called the "Sepp-Alta bottleneck."
THE MAINSTREAM SIBERIAN HUSKY lacks diversity, despite its large population, because it has been severely inbred and strongly selected for seven decades. Often selection is based on traits of superficial appearance that have nothing whatever to do with hardiness and survival ability. Continuous inbreeding in the closed stud books of the American Kennel Club and the Canadian Kennel Club is causing the fixation of genetic defects and the loss of healthy species heterozygosity. It is obvious, if you compare show Siberians with Seppalas, that despite their history of tiny populations and repeated bottleneck events, Seppalas have more diversity remaining than do the show-dogs. Therefore it is unlikely that mainstream Siberians have much to contribute to Seppalas -- "cross-strain breeding" in this instance is a useless endeavour! Selection for appearance affects more than just appearance, since genes for other traits that sit alongside the appearance genes on the same chromosomes get "selected" right along with the ones for colour and markings.
WORKING SLEDDOGS NEED all the hardiness, vigour, and survival capacity they can get -- hence genetic diversity is a major issue for the Seppala Siberian Sleddog. We are fortunate that Seppalas have never been selected for cosmetic superficialities. Nevertheless, the need for additional genetic diversity cannot be ignored. Like the Siberian Husky show-dog, the Leonhard Seppala dog has been bred in a closed stud book for seven decades. It is high time for some new gene inflow to occur. Fanciers have done nothing but make withdrawals from the initial 1939 deposit up till now: it is past time to put something back into the gene bank. The Seppala Siberian Sleddog Project hopes to do just that. We are very fortunate to have located so fine a source of new genes as our new Siberia import SHAKAL IZ SOLOVYEV, who seems to be restoring the Siberian genome of the Harry Wheeler stock from the 1930s to the Seppala Siberian Sleddog breed.
