For many years, researchers at Uppsala University (Sweden) have been exploring the genetic origins of the Scandinavian grey wolf population, which was founded by only three immigrating wolves. In their new study the scientists show that, after five generations of inbreeding, between 10 and 25 per cent of the original genetic variation has been eliminated. The fact that inbreeding is harmful and may directly cause extinction of endangered species is well known. But no research has ever been done to find out exactly how much genetic variation is lost because of closely related individuals mating with one another, or how it occurs. The Scandinavian wolf population was founded by three individual wolves immigrating from Finland in the early 1980s. Geneticists at the University’s Evolutionary Biology Centre have now, by following trends of the population, been able to see the genomic effects of inbreeding over several generations.