How Could this Couple Have 2 Sets of Twins with Different Hair Colors?
The mother of the twins you mentioned above has red hair, which means that she has two copies of the red MC1R gene version. So it would make sense that her children could be red haired too. Redheads can have parents without red hair. But the father is dark-haired. So wouldn’t all of his kids also be dark-haired, since not-red hair is dominant over red hair? Not necessarily. Remember we said that even if you have one copy of the not-red MC1R version and one copy of the red one, you’ll always have a hair color other than red? In genetics, a person who has only one recessive copy of a gene is called a carrier. This would have to be the case in the couple you mentioned. For a dark-haired man to have red-haired children, he would have to be a carrier for the recessive red MC1R gene version. Let’s see why. First off we’ll call the recessive, red hair copy of MC1R, r, and the dominant, not-red copy of MC1R, R. This is something geneticists do to make explaining all of this much simpler. So mo
