I love the Dominant/Recessive model of eye color, and I still teach it because my students always have a lot of questions about whether or not 2 brown eyed parents can have a blue eyed child. However, the model, though useful, is simpler than the actual genetics behind eye color. Two Brown eyed parents can have a blue eyed child, and the Dominant/Recessive model of eye color predicts this reasonably well, while it explains why it is rare. This model, which dates from the early 1900's, oversteps itself however when it predicts that blue eyed parents cannot have a brown eyed child. More than 1 gene is involved (I think the count is now involves 7, but the number seems to go up all the time.), it is not just a matter of B or b.DNA tests have shown conclusively that 2 blue eyed parents can have brown eyed off spring. It is not at all common, but it happens. Curses on all the interfering relatives who upset happy families with genetic models.   See 5 other replies

Yes. No doubt about it. Two brown eye parents can have a child with Blue or Green eyes. It's called the recessive gene. Both Brown eye parents would have to have their own parents or grandparents with blue or green eyes. It has to come from both sides of the parents.Example. My mother's grandfather had blue eyes and blonde hair. And my father's grandfather had green eyes and blonde hair. The rest of us have brown eyes and brown hair. Yet when my sister married her 1st husband who also had brown hair and brown eyes, they ended up having a daughter with blonde hair and blue eyes. Later my sister married her 2nd husband who also had brown hair and eyes. But one of his grandparents had green eyes. So when my sister (who has brown eyes and hair) had a baby with her 2nd husband, they had a daughter with dark hair and green eyes. Just like Twins run in my family due to the recessive gene, so do red heads, blondes and green & blue eye children do. Despite that the majority of us have the dominate characteristics of brown hair and yes. All due to recessive genes.Now here is the flip. If a couple is blonde with blue eyes, they will not and cannot have a brown hair and brown eye child. Just doesn't happen. (if they do, someone has been cheating)All the Dr had to say in the beginning when asked was YES it's possible for two brown eyed parents to have a child with blue eyes due to recessive genes.   See 5 other replies

He was never able to get through his explaination. I believe he said something like "well that's what we used to think.. but now we know it's not that simple", they kept cutting him off before he could explain why it was complex.   See 5 other replies

The doc seemed a bit confused about the definition of dominance as well. Brown being strictly dominant over blue does not preclude the possibility that brown-eyed parents will have a blue-eyed child. Eye color genetics is complicated, but using the 2 gene model and assuming that all the possible brown-eyed genotypes are equally likely for both parents, there's something like a 3% chance of 2 brown-eyed parents having a blue-eyed child (so yes, it's rare). The probability would go up if we knew the grandparents, aunts, uncles, etc. also had blue eyes.   See 5 other replies