Can Two People With Blue Eyes Have A Brown Eyed Child And Why Or How Is This Possible Or Impossible?

23 Answers

Anonymous Profile
Anonymous answered
High school biology makes it seem like genes and eye color are straight forward....however, this site (www.thetech.org) begs to differ, and it is up to you to decide if you can believe this or not:
 
two blue-eyed parents can produce green or brown-eyed children. Eye color is not the simple decision between the brown (or green) and blue versions of a single gene. There are many genes involved and eye color ranges from brown to hazel to green to blue to…

How does eye color work? Eye color comes from a combination of two black and yellow pigments called melanin in the iris of your eye. If you have no melanin in the front part of your iris, you have blue eyes. An increasing proportion of the yellow melanin, in combination with the black melanin, results in shades of colors between brown and blue, including green and hazel.

What we are taught in high school biology is generally true, brown eye genes are dominant over green eye genes which are both dominant over blue eye genes. However, because many genes are required to make each of the yellow and black pigments, there is a way called genetic compensation to get brown or green eyes from blue-eyed parents.
Anonymous Profile
Anonymous answered
Two brown eyed parents can have blue eyed children but two blue eyed parents can not have brown eyed children due to a chromosome mutation found in blue eyed people.
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aileeny
aileeny commented
Amy, Youre right in that 2 brown eyed parents can have a blue eyed child and if they do it proves that neither parent is pure breeding for dominant brown as both have passed on the blue allele.and so are both carriers for the blue eyed gene. // Things are different though for 2 pure breeding (recessive) blue eyed parents , who CANNOT have a brown eyed child as they only have blue genes and cannot pass on a brown ( a rare mutation can alter things ) Normal =2 blue eyed parents =all bb kids
Anonymous
Anonymous commented
Me and my husband both have brown eyes. Our first two girls have brown eyes. Our third(a boy) have blue eyes. Unless they change.
Anonymous Profile
Anonymous answered
My husband and I have blue eyes, both our children have brown. He IS the father. Read on:

"Most of us learned the model for determining eye color that G.C. Davenport and C.B. Davenport devised in 1907. The Davenport model wrongly says brown eye color is always dominant over blue eye color, which means that two blue-eyed parents always have blue-eyed kids. We know better now.

"Although not common, two blue-eyed parents can produce children with brown eyes," says Richard A. Sturm, a Principal Research Fellow at the Institute for Molecular Bioscience at the University of Queensland in Brisbane, Australia.

Eye color is a complex trait. The gene that usually decides the issue (blue eyes or brown eyes) is the OCA2 gene on chromosome 15, but an individual also has other eye-color genes." So it's not so black and white (or brown and blue!) after all.
Anonymous Profile
Anonymous answered
Dragon is right. Eye colour isn't simply determined by one gene, or by dominant and recessive allele inheritance. Eye colour is whats known as a polygenic trait. This means that more than one gene is responsible for the eye colour. There are lots of variations and mutations that can occur by interactions or differences between the responsible genes. This means that with few exceptions, parents with any sort of eye colour can theoretically have a child with most other sorts of eye colour. You couldn't accurately determine the father of a child by eye colour. If you know their blood types, that would be better.
 
Saying that, if you have blue eyes and your child has brown, if one of the possible candidates has brown eyes its probably slightly more likely they are the father than the other. But this alone wouldn't be enough to go on.
Anonymous Profile
Anonymous answered
Could someone comment on this then... I know a couple that are both blue eyed, they have 4 children three of which have blue eyes and one has brown! They all look very much like their mother but the one with brown eyes also has black hair and more olive skin where as the other three have lighter hair and blue eyes (the father was blonde when young).
The mother is dark haired but not black haired... She says the darker looks come from her fathers side of the family.
Is this a possible or is someone not telling the truth???
Anonymous Profile
Anonymous answered
Punnet squares do not apply to eye color, they apply to Mendelian genetics. Yellow vs green peas. How many choices there? 2. Eye color... How many eye colors are there? More than 2.

Save punnet squares and 9th grade biology for wrinkled or non-wrinkled peas, and stop trying to convince people that their mother is unfaithful based on your lack of understanding of HUMAN biology and genetics...
John Profile
John answered
Did you also know that a babies eyes can change color from the time of it's birth.in other words they can be blue and turn brown..eye color really does not tell who the father is.
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aileeny
aileeny commented
Animals eyes change colour from birth too. It is a developmental pigment thing humans are the same
Anonymous Profile
Anonymous answered
I was born with black hair and dark brown eyes, my hair is just sightly lighter than it was at birth but it's still dark. I also have olive skin. Both of my parents were born with clear water blue eyes and blonde hair. They both still have the blue eyes but there hair is now brown. My younger brother was born with the blue eyes and blonde hair too. Both sets of grandparents have blue eyes. All the great grandparents have blue eyes. From a direct blood link as far back as I can go everyone has blue eyes but me! What are your thoughts to that?
Anonymous Profile
Anonymous answered
Two people with blue eyes can have a child with brown eyes. This is because their might be a recessive gene in one of the parents which carries the brown eyes.This character must have come from the grandparents or great-grandparents.
Michael Sholar Profile
Michael Sholar answered
Check out this article for more information:  genetics.suite101.com

Apparently it is possible, though not likely, that two blue eyed parents can have a brown eyed child.  This fact suggests the influence of genes other than just OCA2 (which has been identified) and gey (which is for green pigment).

aileeny Profile
aileeny answered
Two people with blue eyes would not normally reproduce a child with brown eyes.It is not normally possible because a blue eyed parent can only pass on for blue eyes as they have no brown eyed gene in their genomes. So by mendelian rules the answer is that two blue eyed parents (who are both pure breeding for blue eyes ) should always have blue eyed children. However there are always exceptions to any rules and it is possible, infrequently ,for a "blue eyed" gene to change or mutate to brown in either parent ,who could then pass the mutation on.
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Mati green
Mati green commented
PURE BREEDING? Are you talking Aryan? There is NO such thing as pure breeding. EVERY blue eyed person in this world has a brown eyed relative either past or present. I know several couples that both have blue eyes, and they have brown eyed kids. Perhaps you would like me to scan and send you a page or two from my hematology and immunnhematology books?
aileeny
aileeny commented
Comment to Mati, Of course I am NOT talking Aryan . I am talking 1 trait, blue eyes, which being recessive needs a blue gene from BOTH parents to be blue eyed in offsprings phenotype. If u read basic mendelian genetics u will read that a blue eyed person IS pure breeding for their eye colour. , called homozygous recessive, meaning pure breeding recessive. Of course they will have relatives of different eye colours. As u are obviously ignorant of classic eye colour inheritance then leave it out
Mati green
Mati green commented
I am well aware what hematology is. In IMMUNOHEMATOLOGY we studied genetics. Most genetic disorders can be detected in the BLOOD. And I DO know that eye color is genetic and passed down through the DNA. Fact: Two blue eyed parents CAN and DO have brown eyed children., and Two brown eyed parents CAN and DO have blue eyed children. End of subject.
Anonymous Profile
Anonymous answered
While it's possible for 2 brown eyed parents to have a blue eyed child, the opposite is not true. The browned eyed gene is dominant, and if present in a person, the person will have brown eyes. If a person has blue eyes, then the brown eyed gene is not present in the person, and therefore impossible to pass onto an offspring. If you have blue eyes, and your child has brown eyes, it is very, very unlikely that the father has blue eyes.....the brown eyed dominant gene must have come from someone who has that gene to pass on.
Sydney Elizabeth Profile
I just took Genetics and I am pretty sure you can if you have a brown eyed baby with 2 blue eyed parents as long as theres the brown eye trait somewhere in the background. If I'm not right please don't yell @ me I'm only in 8th grade, cut me some slack
Anonymous Profile
Anonymous answered
I agree with Mati_f, I am living proof. My husband and I both have blue eyes, our daughter was born with brown eyes and our son was born with blue eyes.  My father had blue eyes and my mother had brown eyes and all of the children were born with blue eyes. This is a discussion we have often and I have always been told that the eye color can be either color.
Heather Walker Profile
Heather Walker answered
Well I have blue eyes my late husband had blue eyes our two sons have blue eyes but our daughter has brown eyes.Her paternal grandmother is the only other member of our family who had or has brown eyes.My daughters daughter has brown eyes and so does her dad. Work that out.
Mati green Profile
Mati green answered
Absolutely, Yes. Brown eyes are dominate over blue eyes and if there is family history of both blue eyes and brown eyes, you could have the gene for brown eyes even though you have blue eyes.
thanked the writer.
aileeny
aileeny commented
Mati, Sorry but u are wrong. A person who has blue eyes is pure breeding for blue eyes ,called homozygous recessive, because they have NO brown eyed gene (called alleles) in their genome. If they did have a brown eyed gene (inherited either from mam or dad ) then they would have brown eyes as their brown eyed gene B would dominate over their blue recessive gene.b. A blue eyed person is bb and NOT Bb . In other words u cannot carry for dominant brown but u can carry for blue
aileeny
aileeny commented
Mati, As hematology is the study of the blood/// /blood forming tissues and disorders associated with them,then of what possible use would your hematology books be to me.?? I do not understand your reasonings at all.! If u are talking genetics u are way out. Traits from the parents are passed down in the chromosomal dna in the ova and sperm and not in the blood , as u may mistakenly think. Such an ancient belief that is. I am surprised this belief still exists, as dna is so widely known.
Anonymous Profile
Anonymous answered
I agree with mati_f I saw living proof tonight and her parents were definately her parents...eye colour is down to many things other than simply genes.
Anonymous Profile
Anonymous answered
Been looking at this discussion and must say that blue eyes is not a genetic disorder that can be detected in the blood and is way off the point actually. See mati-f comment 18 hours ago!blue eyes are a recessive trait which means that both parents have to pass it on to the child for this trait to take effect . That is why a recessive trait that shows in the phenotype is rightly called pure breeding or homozygous recessive . The blue eyed person has no other colour genes in their chromosomes as if they had they would dominate over the blue
thanked the writer.
aileeny
aileeny commented
Absolutely spot on quest. /////// Obviously u know your eye colour genetics. Nice to see correct facts. Cheers.
Anonymous Profile
Anonymous answered
Definitely yes. Both parent must be carrying a recessive gene for brown eyes and therefore can be manifested in their offspring.
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aileeny
aileeny commented
Brown eyed genes or alleles are DOMINANT and not recessive as you state. It is the blue eyed gene that is recessive. Where two blue eyed parents , who by mendelian rules should have all blue eyed children ,do have a brown eyed child then a miscopying or mutation is a likely answer.
Anonymous Profile
Anonymous answered
It is possible, but not likely.
I don't know how it is possible, but it is very obvious how it is not likely, if you look at a simple punnett square.

The little b represents blue eyes. In order for someone to have blue eyes, they must have two little b's... Because if there was a big B present (which represent brown eyes), it would cover up the little b.
So if both parents have blue eyes, they have to have both little b's.
So bb+bb= all four bb's.

All four possibilities will have blue eyes.

I am NOT saying that there aren't exceptions, I am only saying that the exceptions are rare, and I don't know how they work.

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