White Kermode bears are not albinos as they still have pigmented skin and eyes. Rather, a single, non-synonymous nucleotide substitution in the MC1R gene causes melanin to not be produced. This mutant gene is recessive, so Kermode bears with two copies of this mutant, nonfunctional gene appear white, while bears with one copy or no copies appear black.It is possible for two black bears to mate and produce a white cub if both of these black bears are heterozygous, carrying one copy of the mutant MC1R gene, and both mutant genes are inherited by the cub. Additional genetic studies found that white Kermode bears breed more with white Kermode bears, and black Kermode bears breed more with black Kermode bears, in a phenomenon known as positive assortative mating.One hypothesis is that this happens because young bears imprint on their mother's fur color.
