EN
We examined fluctuating asymmetry of 25 characters of skull morphology (foramina, apertures through the bone for nerves and small blood vessels) to estimate the developmental stability of European bison Bison bonasus (Linnaeus, 1758) (n = 34), cattle (n = 13) and their hybrids (54 hybrids of different generations). Mean number of asymmetrical characters per individual was used as a measure of fluctuating asymmetry. European bison were characterized by a lower developmental stability, compared with cattle. The developmental stability of hybrids was similar to that of cattle and higher than that of European bison. These findings suggest that the genomes of parental forms are similar and that there is no indication of the disruption of genetic coadaptation in their hybrids.