Population Bottleneck

A population bottleneck occurs when the breeding population of a species or a breed is either actually or effectively cut sharply back in numbers, such that dramatically fewer individuals contribute genetic material to succeeding generations. Bottleneck events are very common in purebred dog breeds, in which external events such as wars and economic depressions, as well as changes in breed popularity or in showdog fashions, can cause sudden reductions in the global number of breeding animals. Bottlenecks events increase the effects of genetic drift, as the rate of drift is inversely proportional to the size of the effective breeding population. They also tend to increase the rate of forced inbreeding by reducing the number and choice of available breeding combinations.

The Seppala Siberian Sleddog has numerous bottleneck events in its ancestral history, beginning with the selection of a relatively small number of individuals from the global population of the original Siberian tribal dogs to be imported into Alaska early in the Twentieth Century, and continuing through the Markovo Rescue period when ten so-called Second Foundation dogs became the breeding basis for future generations of Seppala strain Siberians.