Color Blind

Most recent answer: 10/22/2007

My dad is colorblind. He can only see colors if there is only one main color. What I want to know is why my siblings and I are not color blind as well? Thanks!
- Mandy (age 13)
ERMS, Rockford MI
I believe that certain types of colorblindness are due to single-gene mutations. If the mutation happens to be recessive, then if you get a normal gene from your mother, the defective one from your father won’t be expressed. If it’s dominant, then your father would probably also have a copy of the normal gene, and each kid has a 50% chance of getting it. If it’s sex-linked, then the odds change further. So it’s not shocking that you and your siblings don’t have the trait. Some real geneticist (we’re just physicists here) should be able to identify your father’s color blindness and tell you what the odds are for male and female children to inherit it.

Mike W.

(published on 10/22/2007)