Okay guys, PLEASE help me out:
My mother has dark brown eyes, no trace of any other color. My father has blue eyes, again with no other colors, just slight variations in color depth. My biology teacher taught us that brown eyes are always dominant, yet somehow my two brothers and I all ended up with blue eyes (mine, however, do have a thin circle of brown around the pupil). Shouldn’t only one of us (had there been four kids, anyway) have had blue eyes? My teacher wasn’t able to explain it. Then again, he also wore bright turquoise v-neck sweaters with red nylon running pants, so I wouldn’t really have trusted his opinion on anything to do with color anyway. Any ideas?
Eye color is one of those traits that’s ooohhhh-so-close to classic Mendelian inheritance. It generally follows Mendelian patterns but in certain cases doesn’t. It’s actually polygenic. Oh, well, so much for teachers’ examples…
It looks like Mom has one Brown and one Blue gene and Dad has two Blues. Dad always passes the Blue gene to the kids. There is an equal chance that Mom will pass either a Blue or a Brown gene to the kids. When Mom passes a brown gene the kid has Brown eyes, and when Mom passes a blue gene the kid has Blue eyes. So statistically one half of the kids should have Brown eyes and the other half should have blue eyes.
What are the odds of Mom and Dad producing three blue eyed kids. They’re the same as the odds of flipping three straight heads. 12.5%. Not all that unlikely in the grand scheme of things. Less likely things happen all the time without being classified as genetic marvels or freaky mutants.
wevets-Thanks for linking to that page, it really
was helpful! 
And interesting, because now I know the chances of my fiancee and I having brown-eyed kids. The same thing happened in his family, only his dad is the brown-eyed parent.
Now if two blue-eyed parents produced a brown-eyed kid, THEN you’d have a problem.
Not entirely true. The whole thing is a lot more complicated than that. See this page.
Hmmm. Figures.
Both my parents have monochromatic eyes of the “light” persuasion. My mother’s are blue-grey, and my father’s are light blue.
I, however, have grey eyes with yellow and hazel whorls. Sometimes I tell people they’re green.
So, you see, I have mostly blue/grey eyes, but a little bit of yellow/brown got in there.
And your biology teacher couldn’t figure this out? Good luck.
John