GENES PLEASE HELP !!!

[j_todorov]

Can two parents, who have blue eyes ,to have a child with brown eyes?

[kotoreru]

No. Not unless there is a mutation or some other phenomenon somewhere along the line.

This is actually quite interesting: males with blue eyes have been shown to have a preference for females with blue eyes. This is thought to be an evolutionary adaptation to avoid fathering offspring that aren't yours.

(Literature tend to simplify it for Mendelian genetics as: BB = brown; bb = blue; Bb = brown).

[j_todorov]

Thank you very much!!!

[Darby]

It is possible if a parent has a brown allele but lacks working color processors. That should be a rare occurrence (but I've run into it).

[kotoreru]

Darby, do you know of any decent links to sites/papers that explain in detail eye colour heredity etc.? I'd love to know more about this.

[Poison]

yes that's possible. eye color heredity is a bit complex. Multiple modificator genes play role.
That's rara but yes 2 parets with blue eyes CAN have children with brown eyes.

[Poison]

For more info: (university level)
brown color occurance: front layer of iris has melanin
blue color occurance: front layer lack melanin. Back part has it.
Multiple modificator genes are genes that are not alleles of a trait but playes role on phenotypic expression. They affect pigment production, tones etc. (that's how colors other than blue and brown occurs)
Let's say both of the parents have blue eyes. But one of them (or even both of them) can be Bb but because of multiple modificator genes pigment production can be blocked. So his/her eyes appears to be blue. He/She can give that B to his /her child. So the child now carries the dominant allele B. And the eye color is brown.
Hope this helped.

[MrMistery]

@ozge
I may be wrong, but from what i remember, if a person has blue eyes he must be recessive for all 3 genes involved. So that would mean it is indeed impossible for the parents with blue eyes to have a brown-eyed child.

[Darby]

Some links (but don't expect it all to make sense - it is biology, after all):

http://www.wonderquest.com/eye-color.htm

http://news.bbc.co.uk/2/hi/science/nature/6195091.stm

http://www.hhmi.org/cgi-bin/askascienti ... s_044.html

http://medicine.jrank.org/pages/2231/Ey ... Color.html

A bit on the evolution:

http://www.news-medical.net/?id=20699

[Poison]

@ozge
I may be wrong, but from what i remember, if a person has blue eyes he must be recessive for all 3 genes involved. So that would mean it is indeed impossible for the parents with blue eyes to have a brown-eyed child.

Are you sure? I think you are worng. What I wrote is something that is told during our genetic classes. If someone is Bb but melanin production on the front layer is blocked by another gene eyes will appear to be blue. What's more, 2 alleles (brown and blue) and many multiple modificator genes are involved in the heredity of eye color. Some change the tone of the pigment or amount of production. And that's how other colors form.