Glacier bears are an Alaskan subspecies of the American black bear. Glacier bears have a rare dark grayish-blue fur. Some glacier bears live in the same areas as black bears. A glacier bear and a black bear can mate and produce cubs. Studies show that the allele for black fur is dominant and the allele for gray-blue fur is recessive. The gene for fur color can be represented by the letter G or g. The genotype for gray-blue glacier bears is . *