Chris Morgan67 said:but when it comes to eye color, there’s no debate. two brown-eyed parents can’t have a blue-eyed kid
Actually, it's the opposite. Two blue-eyed parents can't have a brown-eyed kid.
For blue eyes to show up, the kid has to inherit the recessive gene from both parents. So, a blue-eyed person carries two recessive genes. Let's say that person is the father in this scenario.
If you pair his two recessive genes with two more recessive ones (from the mother), the kid isn't getting a dominant brown-eye gene from anywhere.
In the case you're talking about, it's not just possible—it's totally normal. A dad can carry both the brown and blue eye genes. He'll have brown eyes because that's the dominant trait. If he has kids with a woman who has the same setup (brown and blue genes), there's a one-in-four shot one of those kids ends up with blue eyes since the recessive genes hit the jackpot.
, I'm pretty sure hair color isn't just down to one single gene. But whatever... 🤔
Is it a huge outlier? How old is the kid?