Genetically impossible? Two blue-eyed parents having a brown-eyed child?

[jread]

Everything I have ever learned about genetics tells me that there is no way two blue-eyed or green-eyed parents can have a brown-eyed child. Blue and green are recessive, with brown being dominant over both. Now, it will work the other way around, but you can't go from recessive to dominant with eye color (as far as I know).

Is something like this even possible? Is there something I don't know? Right now I'm trying to figure out how:

Parent 1: bb
Parent 2: bb

Could result in:

Child: Bb


(reason: I know a family in which the father has light blue eyes and the mother has blue/light green eyes, but their daughter has dark brown... almost black.. eyes)

 

[DeadByDawn]

What color eyes does the mailman have?

 

[Xyo II]

adopted? that or an abnormality.

 

[Scarpozzi]

You ain't da daddy. Ho been sleepin' round.

---

You ain't da nice guy. Yo, you be postin' elsewhere fo' da nex' week.

AnandTech Moderator

 

[jread]

Originally posted by: Einstein Element
adopted? that or an abnormality.

She looks like her mother as far as her features, but she has very dark eyes.

 

[mordantmonkey]

i don't think eye color is a simple recessive/dominant trait

 

[amish]

impossible

bb x bb /= BB or Bb

time to take it to springer

 

[theNEOone]

this also goes against what i've been taught. the only thing i can think of is that eye color isn't determined by a single gene, but is instead a more complex interaction - something they left out in school so they could simplify the concept. in some cases this is true. take for example albinos. even if eye color was usually determined by a single gene, albinism removes the pigmentation entirely.


=|

 

[z42]

Genetics isn't as simple as that, especially in human DNA. While it is very unlikely for two light eyed people to have a brown eyed child, it isn't impossible. Also, depending on the age of the child, her eye color may change as she gets older.

 

[Injury]

... and you gotta factor in that some people's eyes completely change color with the seasons and in aging.

 

[Syringer]

Rare certainly, but not impossible.

 

[Aves]

Text

 

[nageov3t]

not really as simple as that... hell, my mom's got blue eyes, my dad's got brown eyes, neither of their parents have green eyes, and I somehow ended up with green eyes.

/shrug

 

[ArchCenturion]

My mother has blue eyes, my father has brown eyes.

I have 3 brothers, we all have blue eyes.

 

[Bootprint]

Google Answers

For 5 dollars you question has been answered.

 

[djheater]

Originally posted by: ArchCenturion
My mother has blue eyes, my father has brown eyes.

I have 3 brothers, we all have blue eyes.

I have blue eyes my wife has amber or hazel eyes.
One with dark brown two with blue.

 

[Runes911]

Originally posted by: Bootprint
Google Answers

For 5 dollars you question has been answered.

You paid $5 for him to get his answer?

 

[theNEOone]

as i suspected:

http://www.athro.com/evo/gen/inherit1.html#uncertainty

Eye color is more complex than two genes

In humans three genes involved in eye color are known. They explain typical patterns of inheritance of brown, green, and blue eye colors. However, they don't explain everything. Grey eye color, Hazel eye color, and multiple shades of blue, brown, green, and grey are not explained. The molecular basis of these genes is not known. What proteins they produce and how these proteins produce eye color is not known. Eye color at birth is often blue, and later turns to a darker color. Why eye color can change over time is not known. An additional gene for green is also postulated, and there are reports of blue eyed parents producing brown eyed children (which the three known genes can't easily explain [mutations, modifier genes that supress brown, and additional brown genes are all potential explanations]).

The known Human Eye color genes are: EYCL1 (also called gey), the Green/blue eye color gene, located on chromosome 19 (though there is also evidence that another gene with similar activity exists but is not on chromosome 19). EYCL2 (also called bey1), the central brown eye color gene, possibly located on chromosome 15. EYCL3 (also called bey2), the Brown/blue eye color gene located on chromosome 15. A second gene for green has also been postulated. Other eye colors including grey and hazel are not yet explained. We do not yet know what these genes make, or how they produce eye colors. The two gene model (EYCL1 and EYCL3) used above explains only a portion of human eye color inheritance. Both additional eye color genes and modifier genes are almost certainly involved.

=|

 

[theNEOone]

Originally posted by: Scarpozzi
You ain't da daddy. Ho been sleepin' round.

---

You ain't da nice guy. Yo, you be postin' elsewhere fo' da nex' week.

AnandTech Moderator

omg, give me a break....
:roll:

what "offense" did he commit?


=|

 

[n19htmare]

ok you got me........i'm da daddy.

 

[AgaBoogaBoo]

edit: nvm

 

[moshquerade]

Originally posted by: n19htmare
ok you got me........i'm da daddy.

oh snap

don't even suggest that. :Q

 

[Bootprint]

Originally posted by: Runes911

Originally posted by: Bootprint
Google Answers

For 5 dollars you question has been answered.

You paid $5 for him to get his answer?

someone else did, at least that's what it appears to say near the top of the page.

 

[Eeezee]

only one way to find out, get a blood test and find out if you're really the father. You can still love the child, but it would be necessary to find out the truth imho.

It will be useful if you feel like leaving her then,since you won't owe child support

 

[Shawn]

Originally posted by: Scarpozzi
You ain't da daddy. Ho been sleepin' round.

---

You ain't da nice guy. Yo, you be postin' elsewhere fo' da nex' week.

AnandTech Moderator

Banned for that?