Tag Archives: ImpromptuResearch

Figuring out my parents’ eye color alleles

A couple days ago, Elisha, my sister ( @animalfreak9 ), commented on one of my blog posts. She asked what the chances of her inheriting hazel eyes was. At first, I dismissed the idea as impossible. I didn’t think it could happen with my mom having blue eyes. But then I did some more research.

I learned that brown eyes are dominant over all, hazel and green are dominant over blue, and blue is completely recessive. This means that for Elisha to have hazel eyes, she would only need one hazel allele from my dad. My mom’s blue eyed allele that my mom had to of given Elisha wouldn’t have affected it (My mom’s eye color genotype MUST be bb, or blue and blue. This is because to have blue eyes you must be homozygous(have two of) recessive (blue eye alleles).)

That’s right. To have blue eyes you have to have 2 blue eyes alleles. That means, you guessed it, my dad needs to have a blue eyed allele! Otherwise, Elisha and I wouldn’t have blue eyes. The other allele my dad has would overpower my mom’s blue allele.

Now I knew that my mom’s genotype for eye color is bb (blue eye and blue eye) while my dad must have a b allele as well. There isn’t any way his genotype is bb, though, because he has hazel eyes! This means he MUST have a hazel allele! That means that my mom is bb and my dad is Gb (hazel and ¬†blue). That results in a 50% chance of Elisha (or me, for that matter) having hazel or greenish eyes. TA DA!


Keep in mind I started learning about genetics this summer. I am also 13 years old. There is a high chance that I messed up/was misinformed in some degree/read the wrong answer on the internet/am just plain wrong and am making stuff up as I go unknowingly.

But, on the other hand I could be totally right!