Wolf diversity destructed by hunters
Many species face current populations declines, which is often a consequence of human behavior e.g. hunting, habitat destruction. This leads to genetic bottlenecks. Once genes have been lost from a population, they are irreversibly lost, and the population left behind is weaker and less able to adapt to future changes in their environment.
Wolves in Europe are currently experiencing this genetic bottleneck, due to historic hunting and the subsequent slow re-population. In response to this, scientists from the University of Lausanne sequenced the DNA of 150 wolves from museums all across Europe. Their objective was to find out if the decline in the wolf population during the last two centuries influenced the wolf’s genetics.
The study shows that just one century ago, the genetic diversity of the wolf was more than double that of the current wolf population. At the same time the individual wolves across Europe were genetically more similar to each other than today. This suggests that there was more gene flow in the past, and that wolf populations were larger. The findings are in line with the prosecution of the wolf on the whole continent in the 19-20th centuries. The results of the study also shows that the Italian wolf sub-species used to be present in other parts of Europe as well.
The scientists also found significant genetic differences between modern Eastern and Western European wolves. Hunting nearly completely eradicated the wolf in Western Europe in the 19th and 20th century. As a consequence, its genetic diversity significantly decreased at the turn of the 20th century. The re-population by the remaining wolves is the cause for the significant changes in modern wolf genetic composition. This development is in contrast to the Eastern European wolf populations, which have never been hunted to such an extent as the wolves in Western Europe. These Eastern European populations still show a similar genetic diversity as a hundred years ago.