Codominance in Erminette Fowls: Genetic Basis of the Erminette Pattern

What genetic basis of the erminette pattern is suggested?

Based on the cross of two erminettes producing 48 progeny, consisting of 22 erminette fowls, 14 black fowls, and 12 pure white fowls, what genetic basis of the erminette pattern is suggested?

Genetic Basis of the Erminette Pattern:

The erminette color pattern in fowls suggests a codominant inheritance pattern, where neither color is dominant, resulting in offspring that exhibit both colors (as seen in the speckling of the erminettes.) This produces a non-Mendelian inheritance pattern of erminette, black, and white offspring.

Explanation:

Based on the proportion of offspring from the cross of two erminette fowls (22 erminette, 14 black, 12 white), it appears that the erminette color pattern in fowls is due to a codominant inheritance pattern. Like Mendel's experiments on inheritance patterns, when two individuals with different alleles mate, the offspring's phenotype can mirror that of both parents, which is what we're seeing in the erminettes that are speckled black and white.

To apply some of the ratios seen in Mendel's pea plants, we can view the erminette as akin to the hybrid plants in Mendel's F1 generation that saw a combination of both parent plant colors. In this case, the bird's speckling phenotype results from both black and white colors being present and expressed, with neither color being dominant and thus not completely masking the other color. This results in the erminette pattern.

Overall, this example of codominance is evident in the production of erminette, black, and white offspring in the ratio of 22:14:12, suggesting a non-Mendelian inheritance pattern distinct from simple dominance and recessive relationships.