Aspects of the Genetics of European Bison

Abstract

From a genetic perspective European bison (Bison bonasus) is one of the most severely impoverished species known. After extinction in the wild in 1919, its population was restored based on the descendants of just a few individuals. Additionally the share of the individual founders’ genes in the extant population is extremely unequal and a definite majority of them come from just two founding individuals. Low number of founders inevitably results in mating between relatives and inbreeding. Surprisingly, in spite of the high inbreeding level and low genetic variation, the species does not seem to show detectable signs of inbreeding depression. As an effect of mating in relatedness, European bison individuals are so genetically similar that standard molecular techniques are not sensitive enough to distinguish them. The fact that they are so similar genetically means that in the case of a potential epizootic event their organisms will behave in a similar way, which is not necessarily beneficial for the species. For this reason, the low genetic variation of the European bison remains one the major threats for its survival and why, in spite of the relatively high number of living representatives, European bison is still considered as a species facing a high risk of extinction in the wild.