Join Date: Nov 2004
Location: Hiding from the children...
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...my brain, that is.
Ok, I meant well but I was being sloppy.
My big mistake was saying 0% chance of this and 100% chance of that, because even though that is the way I was taught, we all know that there are exceptions, so this is oversimplified at best.
For one thing, we may express an eye color for reasons having nothing to do with the "eye-color genes" we inherit.
EXP: A brown eyed person, we assume, has inherited a gene that causes melanin to deposit in the iris. This gene is dominant. The blue eyed person, it's assumed, doesn't have this gene. But just as an albino is born without pigment, causing pink eyes, it is possible for a baby's melanin production to fail (for example), causing blue eyes in a child with nothing but brown-eyed ancestors on one or both sides... but remember this is not the result of eye-color gene inheritance; the child inherited the dominant gene/s but other mechanisms in the body didn't cooperate... So this child didn't inhered the genes for blue eyes, and cannot pass them on. They may, however, pass on whatever it is that caused their melanin failure, if it is in fact an inherited trait.
There are similar theories to explain 2 blue-eyed people having brown-eyed children (one of which involves the milkman, but we won't go there). These all assume that current thinking is correct, but other issues get in the way and muck things up... or that there is a such thing as brown recessive, which is truly a hazel variation that appears brown/golden.
As far as green as go:
Yes, I was wrong to lump them in with blue, even though green genes are believed to be nearly identical to blue. It is the way they are expressed that differs. BTW, they are only co-dominant with blue, not brown... "Hazel eyes (Bg*) can be produced by crossing an individual who is heterozygous Bb with and individual with Green eyes." Could this explain your MIL's blues? Who had hazel eyes among her parents/grandparents?
OMG, you had this nice poll about eye color, and I really thought I was being helpful when I posted last night... this is such a confusing issue and even those who teach it agree that there is a lot of supposition and error involved. If you can take green/hazel/golden eyes out of the equation (my mom's side is Latin/African, my dad's side is Norwegian, so I have nothing but blue and dark brown), you can draw up a pretty simple pedigree showing the likelihood of your child's eye-color outcome, assuming there is no phenomenon that interferes with gene expression. Green eyes just stir the turd so much I wouldn't bother.