Increasing levels of inbreeding is a threat against the viabi lity of the Scandinavian wolf population. A study just coming out in the new journal PLoS ONE now demonstrates that inbreeding is not affecting the wolves as badly as expected. The results show that it is the most genetically variable wolf individuals that are recruited into the breeding population. An important consequence of this action of natural selection is that the negative effects of inbreeding are accumulating much slower than previously believed.
The wolf was exterminated in the Scandinavian peninsula by the 1960-ies. The present Scandinavian population of approximately 150 animals was founded by three immigrants from the larger Russian-Finnish population; a pair around 1980 and a single male ten years later. With so few individuals founding the population the level of inbreeding is high. By the use of DNA-analyses the research team has previously reconstructed a pedigree of the whole population. This kind of detailed information about wild animals is quite unique, but a necessary prerequisite for calculations of so called inbreeding coefficients.
- The inbreeding coefficient is a measure of the proportion of the DNA that is inbred. It varies between 0 and 100%. If a brother and sister are mating, their offspring will have an inbreeding coefficient of 25%. This is about the average level for the present wolf population in Scandinavia. And our analyses have shown that inbreeding is negative, inbred wolves produce less number of pups, says Staffan Bensch, one of the spokespersons of the research team..
The inbreeding coefficients are calculated from the sorted out pedigree. Another way to estimate the proportion of the DNA that is inbred is with DNA-techniques. The research team used samples from blood, hair and scats and examined the DNA at several places to measure the level of genetic variation of individuals. Together with the previous analyses based on inbreeding
Contact: Staffan Bensch
Public Library of Science