Genetic Diversity
When working with a very small population, the first priority is preserving what genetic diversity is available for as long as possible. In the past, individuals merely bred whatever two animals they happened to have. This led to some pairs having lots of offspring, and others none. This is the way genes are lost from the population. The New Guinea Singing Dog Conservation Society (NGSDCS) has a stud book for NGSDs with known pedigrees begun with Dr. I. Lehr Brisbin. Now the stud book includes some individuals that tested genetically pure based on the Embark test.
The NGSDCS’s breeding plan was developed on the principles of population genetics. These principles include maximizing genetic diversity by: (1) including at least two offspring of every pair in the program; (2) not letting any one pairs’ offspring become over-represented in the breeding population; (3) choosing the least-related breeding pairs. Genetic diversity is important because it increases the chance that not all the members of the population would be affected by any one health problem or illness.
Such over-representation of one pair’s genes in a small population can result in loss of the rarer genes because specimens with some additional genetic ancestors are not used for breeding and this actually works against the long-term good of the NGSD.
The North American NGSD population had two littermate original founders, which came from the Taronga Zoo to the San Diego Zoo in ~1957. The USA only had offspring of this pair to breed until the 1980s, when a female, Olga, was imported from Germany into Kansas. The German NGSDs came from a different area of the island, and so were unrelated to the Taronga line. Adding Olga increased the captive North American NGSD genetic diversity by at least 33%. Dinkum, Olga’s mate, and a male named Dingo were the last known original Taronga line breeding males.
One other male and female were imported from Taronga in the late 1980s but the male sired only one litter of which only one offspring went on to produce pups, and the female had one litter with no offspring being used for breeding. So essentially all NGSDs were as closely related as littermates. In the 1990s a male, Darkie, was imported from New Guinea first to Canada, where he reportedly did not reproduce, and then to the USA by Dr. I. Lehr Brisbin. Darkie reportedly had a Taronga sire and an unrelated dam. At Dr. Brisbin’s facility in North Carolina, Darkie sired several litters out of Scratchley, who was an offspring of Dinkum and Olga. These puppies had 25% of genes unrelated to other NGSDs in North America.
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Marlin and Samber. They were a mix of all available genetic lines in North America. They produced two litters.
The NGSDCS program was started with the offspring of Darkie and Scratchley. These were bred to the least-related (for at least two generations) Dinkum & Olga descendents. Subsequent generations have been judiciously bred together. An unrelated male, one of the last of two breeding-capable males in Europe, was imported by the NGSDCS in 2005 from Germany to increase genetic diversity. This male, Benji, was from the same lineage as Olga, but there is only a small chance his great-grandparents were the same specimens as Olga’s parents. Unfortunately, Benji proved to be infertile.
We believe this pedigree or genetic testing based plan is the best way to preserve what we have in the North American population until additional stock can be obtained from PNG. The NGSDCS’s intention has never been to breed NGSDs just for the sake of making more of them. The breedings we approve or sponsor are intended to maintain genetic diversity in the population for good health. Those individuals that cannot go into the program, are spayed and neutered to eliminate the chance of accidental litters.