DNA research and wolves

Genetic methods are used in wolf research to determine the purity of the species. DNA analysis is an internationally used method for recognising genetic differences and it has long since replaced comparisons made on the basis on external features.

Genetic methods help researchers identify wolves

Every wolf specimen received by National Resources Institute Finland (Luke) has its skull measured and tissue samples taken for the purposes of DNA analysis. The DNA analysis is conducted at the genetic research unit of the University of Oulu, which has at its disposal state-of-the-art equipment and internationally renowned scientific know-how. Luke does not conduct its own DNA analyses. Instead, the institute stores tissue samples from all specimens it has received on a permanent basis. The institute does not have the capability to store entire carcasses on the long term. The upkeep of actual scientific collections is the responsibility of Finland's national history museums, where a large part of the wolf skulls and pelts received by Luke are put on display.

The samples used to chart the DNA of Finnish wolves come from hunted wolves or wolves found dead in the wild. For the purposes of determining the hereditary diversity of our wolves, historical samples found in museum collections and samples from animals living in the wild are also used.

The reference database used in DNA research is comprised of the sample types mentioned above. Reference material from Scandinavian and Russian wolves is also included. The database contains information on over 500 wolves, and each sample contains DNA and other individual features as well as geographical location data. The reference database is used to get an understanding of the variance of hereditary features in wolves.

Percentages show the degree of similarity with the reference material

In DNA analysis, the probability of a wolf specimen belonging to the reference group is represented with a percentage. For example, if a wolf specimen’s percentage is 95, its probability of belonging to the reference group is 95%. This probability can never reach 100%, as each individual wolf's genetic makeup is different and there can never be two absolutely identical animals in the reference database. It is important to note that this percentage does not represent the wolf's "degree of hybridisation".

The same result can be achieved by comparing any pedigree dog to a reference database comprising of other specimens of the same breed, for example. A 95% result does not mean that the dog is 95% purebred and 5% mixed. Similarly, if the probability of person A being the father of person B is 98%, it does not mean that 2% of person B's father is someone other than person A.

Dogs and wolves are clearly separable using genetic methods

Finnish wolves form a very tight group that is clearly distinct from dog breeds such as the Siberian Laika and the German Shepherd that have been used as control groups. Hybrids have been very easy to recognise. Between 1996 and 2010, three wolf-dog hybrids have been found in Finland (Kuhmo 2010, Juva, 2005, Parkano 2010). The mitochondrial DNA in all three cases has been from the wolf, which means that all of the hybrids were the result of mating between a female wolf and a male dog. Research conducted elsewhere has confirmed that hybrids are typically the offspring of female wolves and male dogs.

DNA samples collected from Finnish and Nordic wolves have also been sent to independent foreign researchers.

The most comprehensive study on dog and wolf relationships worldwide was published in the renowned Nature journal a couple of years ago. The study was the work of an international research group and its findings also demonstrate that wolves and dogs may be distinctly separated from each other with the help of genetic methods.

The study found no significant differences between the wolves of Northern Europe and the wolves living in other parts of the world; Nordic wolves are no closer to dogs than other wolves. Another international study published last year corroborates this as it also indicated that Finnish wolves do not differ from the wolves of Eastern Europe.