How can two brown-eyed parents have a blue-eyed child?

Answer 1

Well, you will hear many answers to this, and one thing that you will notice is that everyone who says it is possible says just that, "it is possible, and anyone who tries to correct me is stupid." However, those who say it is possible go into great detail and science explaining their answer. That is something I wanted to point out. Anyways, the answers you hear will be something like, "yes, it is possible," "yes it is possible, and it happened in my family," "It is completely impossible, there must have been an affair in the family," and something in great confusing detail that I won't go into.

All of those answers are wrong, though some are close. The first step to understanding the answer is knowing that 1. Brown eyes is a dominant trait, and 2. blue eyes are a recessive trait. What that means is that a dominant trait will always show, and a recessive trait will be taken over by the dominant trait. So, if you have two dominant traits, obviously, that trait will show, and if you have a dominant and recessive trait, the dominant one will show there as well. So the only way for a recessive trait to show would be if there were two recessive genes present, and that's all the eye genes in a human- two. So if both parents had blue eyes, no matter how close or far away the brown eyed gene is in the family, the parents will always have two blue eyed genes, because that is the only way they can have blue eyes. So in other words, all the genes that the babies get will be blue eyed ones, because the parents can't pass on the brown eyed trait, because they don't carry it. Because if they did carry the brown eyed gene, they would have brown eyes.

Now the reason that two blue eyed parents sometimes have brown eyed children, is for the reason of genetic mutation. That is when genetics completely ignore the laws of nature, and things happen that weren't supposed to. This is a rare and unexplainable phenomenon, but it happens.

P.S. I would use this as a debate, it is really fun to prove. I tried it on my friend (who is twelve), and by the end, she was yelling at me, saying I was giving her a headache, trying to change her point, and even sticking her fingers in her ears saying "I'm not listening!"

Answer 2

Two brown-eyed parents can have a blue-eyed child if they both carry a hidden recessive gene for blue eyes. If each parent passes on this recessive gene to the child, then the child can have blue eyes, even though the parents have brown eyes.

Answer 3

yes and technically there could either be a 1/8 chance or a 1/4,1/2 chance if both parents have the gene for blue eyes. they didn't get it because they had either no chance for one or 1/4 for each

Answer 4

yes You have to have blue eyes in your genes for example a grand parent. My parents both have brown eyes but my brother has blue eyes. That only happend because my mothers mother has blue eyes and my farthers farther has blue eyes

Answer 5

A blue eyed child can result from two brown-eyed parents if both have a recessive gene for blue eyes. The father's parents and the mother's parents must have one recessive gene for blue eyes between each couple. For this reason, they may have large families of brown-eyed children and be unaware of any blue eyed ancestors, but the blue-eyed child only needs one hidden gene from each parent. If they look hard enough into the family tree, at least one blue-eyed relative (direct ancestor) will show up on each side of the family.

The normal answer you get in high school Biology class is no, but genetics is not that simple. For example one of the parent may have genes for brown eye colour but for some enviromental reason that colour was not expressed giving blue eyes but still pass on brown eye colour. A second possibility is both that the father and mother has a malfunctioning gene for brown eye colour but the gene has it's malfuntion on different places in each parent. During recombination the genes can swap parts and produce a functioning gene giving brown eyes to the child. So yes two blue eyed parents can have a brown eyed child.

The two brown-eyed parents can be heterozygous for blue eyes. So each child would have a 25% chance of having blue eyes.

Answer 6

yes. It's true. ancient ancestor have a genetic gene of blue eyes. Even though parents don't have blue eyes.

Answer 7

If they have a gene of blue eyes, then if both parents have the gene the child will be blue-eyed.

Answer 8

I believe so, through recessive genes. It happened to my parents. None their kids (my siblings and I) had the same eye color.

Answer 9

Because maybe some of their relatives have blue eyes.

Answer 10

Not likely