Blonde, blue-eyed half-Japanese kids

Sorry....I was mixing doubling with squaring :-( Still, the point realy was that we have a lot of ancestors and it only takes one distant one on each side for the blue eyed gene to pass down.

Really? So if you have even one blue-eyed ancestor, you have a chance of having blue eyes or having children with blue eyes?

What about mixing between the races? If I have an ancestor who is African, for instance, but it was 10 generations ago and I look completely Asian, would it still be possible for me to have an African-looking child even if I were to marry a fellow Asian?

As I understand it; if you (a person with brown eyes) have had one ancester with blue eyes, you may have the blue eyed gene.
If you have a child with someone (with brown eyes) who also has the blue eyed gene, you will have a one in four chance of a blue eyed baby. You will have a two in four chance of having a brown eyed baby with the blue eyed gene, and a one in four chance of a brown eyed baby without the blue eyed gene.
Each time you have a baby together the chances will be the same, so four babies will probably not give you one of each!

I don't know which race genes are regressive, but it is true that a regressive gene can be carried unknown for generations, and only show when two people with the same gene have a baby together. Some illnesses are carried like this.

What you say is correct, Apples, for any trait that is goverened by just one gene (such as all those characteristics of peas that were studied by Mendel). There's a neat 1 - 2 - 1 (out of 4) probability of outcomes, of course, just as you say.

My understanding of eye color is that there are several genes involved, though, so it may be harder to predict. If the genes are located very close to one another they may tend to get distributed as one would be.

Anyhow, the question of eye color among the Japanese (or hair form, which is also more variable among the Japanese than might be expected for an island population) is all tied up with the question of the ancestral origins of the Japanese people, which is a fascinating and hotly debated topic.

http://en.wikipedia.org/wiki/Japanese_people#Origins_of_Japanese

My Okinawan wife asked this question today (is it possible for our next kid to have blue eyes?). I remembered the Mendel charts from highschool, so my blue eyes began looking on the internet for an answer.

This website not only has an explanation, but also a neat little calculator: http://www.athro.com/evo/gen/genefr2.html

The calculator gave us 30 kids (hahahaha), and all 30 of them had brown eyes.

A Japanese person that has reddish-brown or yellowish-brown may be considered "hazel" by Japanese standards but this is not "hazel" by American or European standards. Hazel is when the eye is actually green and brown but the eye is a light color. So if a European or American saw a Japanese person's eye they would say it's brown, not hazel. It is just a matter of different viewpoints.

i just found this and thought i should comment.
my father is 100 percent japanese. of course you have to take into consideration of where japanese people come from. but that aside hes japanese and my mother is white and i have very blue eyes. my son also has blue eyes and his mother is 100% korean.
so yes it is totally possible. heres a pic for referance http://img.photobucket.com/albums/v165/jdmdrift/pe.jpg

My grand father was from Kumamoto and was pure Japanese and he had icy grey eyes.

'' normally the blue eye gene is dominate''

Prof,
If memory still serves me correctly....
AA -- Dominant = dark brown
Aa -- Dominant-recessive = brown, green, hazel
aa -- recesive = BLUE -- meaning, this gene must be present in both parents' genotype; it is not dominant; it 'emerges' only if combined with other recessive (bleu) allel...

you guys should post some pictures up of those eyes! i've never seen an east asian person with any other colour of eye than brown. this should be interesting.

I know some small groups of isolated asians have coloring like Europeans, like blue eyes, red hair and and brown hair.

The Ainu (native asian Japanese) have been known to have blue eyes, red hair, and brown hair. The Japanese are genetically mostly Korean and Ainu. Genetic and skeleton tests have proved the Japanese are a mixed ethnicity.

The Ainu are said to facially look like Europeans, and are uncommonly tall and hairy.

Most Ainu today don't tell their children they're Ainu because of racism against Ainu in Japan.

Findings show that blue eyes and blond hair occur naturally in every human population to a certain extent, as it is a fairly rare mutation in the human genome. Northern Europeans have the highest percentage of Blond hair blue eyes due to geographical/historical genetic drift. blond ahir and blue eyes does appear naturally even in african populations, but is almost instantly wiped out due to the disatvantage in that type of climate (i.e. being blinded and sunburnt).

It is not suprising then to find that even asians can have blond hair blue eyes, as it occurs even if all anscestors have dark hair dark eyes. the gene may be present and is only able to phenotypicaly show itself when in contact with another similar gene. In European populations (mostly northern) blond gene is so prequent that almost all the population is carrying the gene even though its not phenotypically expressed.

but comes to no surpise to me that blond haired and blue eyed asians exist, because of the genes own natural occurunce in all world populations, but may be helped to phenotypically show itself when in contact with european genes.

dunno if this helpes, but i tried my best

being of Scandinavian and British origin (i now live in portugal) I have Blond hair, with some hints of red, and blue eyes.

I am moving to Japan soon, and I just wanted to ask what sort of response i would get from japanese people when they see my blond hair blue eyes. here in portugal where blond hair is quite rare, people love playing with my hair (even though i am 20 years old) and commenting on its colour.
Will I be recieving the same sort of reception in Japan or not?

Tristan: I doubt that you will have people just coming up to you and playing wtih your hair, if that's what you mean. It is always possible that if you make a very close friend in Japan, they might do that. But for the general populace, Japan is more of a polite society than most, in terms of touchiness, to the extent that I went to a bar the other night with some friends and met a few Japanese boys (I am doing an abroad program in college and am living in Kyoto). One of them asked if I would be back in the bar next week, and I said sure, and then he and his friends walked me out to a cab (my friends left in a cab about two minutes prior), and as soon as he rather suddenly gave me a 1 second, very casual by my standards hug (no torso contact, just an arm around the shoulder and a quick squeeze), instead of thinking that he was drunk and/or just friendly, I suddenly thought, oh man I just agreed to a date, didn't I? (Obviously I don't know as much about Japanese culture yet as I'm making myself sound, if I didn't catch that until the hug). His friend, who I had talked to a lot more that night but wasn't the one who asked if I would be back next week, didn't come near me while I was leaving. I could be wrong (I guess I'll find out on Friday night), but from my own experience and feeling, casual touching isn't really done here (hence why I thought that this boy thought we had cemented some kind of relationship there. Either that or he was emulating my male friends who had just left). What Japanese people WILL do is stare at you, maybe whisper about you, maybe a child will yell to his parent GAIJIN (foreigner), sometimes if you pass a class of schoolgirls, they might all start yelling HELLO! at you, and some really friendly people will want to chat with you just cuz you look foreign and maybe practice their english. No touching, though, unless you've established something like that.

Sorry for the long convoluted explanation.

Now, about the eyes thing. I can't claim to know everything about it, but I am a biology major. Eye, skin, and hair color are controlled by multiple genes each. Each of these genes have multiple alleles that have varying levels of dominance and recessivity. These genes work together in what are called ''epistatic interactions.''

If you work it out, even a simple epistatic interaction, 2 genes, only 2 alleles each (a dominant and a recessive) you get nine different physical outcomes. Now I'm sure that the genes for eye color work more subtely and more complicatedly than that. That bullshit they feed you in middle school bio class about a mendelian chart showing brown eyes being dominant and blue eyes being recessive is just that: bullshit. It's like telling a half truth. It's only true to an extent (this extent being that blue in general seems to be more recessive than brown). The only reason why that example is used is because all little kids know that lots of people have brown eyes and fewer people have blue eyes. Hell, my teacher even threw in green eyes as being even more recessive just for good measure.

But that's not how it works, and that's why we DO have such a variance in eye color. Eye color is never used as an example for simple dominance or recessivity in more advanced biology classes. Even albinoism (lack of color pigment) has it's degrees in eye color. I mean, think of it. Genes are PRECISE, incredibly so. The person who first posted this question simply asked asked with the consideration of brown as dominant and blue as recessive. If there was one gene involved, and only this brown allele and this blue allele, then three-fourths of the world would have the exact same shade of brown eye color and one-forth would have the exact same shade of blue. The only variance would be caused by mutation of the gene, which wouldn't be unlikely because having a different eye color usually won't kill a creature. But since the rest of us would be the same, we would probably notice immediately, point and yell FREAK, shun the poor kid, and they wouldn't be able to reproduce to send the new allele onwards (natural selection at it's finest).

I do in fact vaguely remember some kid asking in class about how eye color epistatic interactions work probably thinking that it was a simple enough question, and the professor said that he would not be able to go into that. I'm not totally current on literature, but I'm pretty sure that scientists, even specialists researching this exact, specific topic about eye color genes and their interactions, still don't quite know what's going on.

All of us have the same exact color pigment in our eyes. It's not like in plants, where GREEN pigment is CHLOROPHYLL and ORANGE is CAROTENE (orange like carrots). Eye color is based on placement and amount of this pigment, I think. So your parents are always passing down the same pigment as theirs, there are just other factors involved, if this makes it easier to understand. There are many different options for why a child would have an unexpected eye color, the most obvious being ancestry that wasn't considered before. Considering all the genes that could be involved in eye color though, it could just be a very rare combination of genes that isn't really seen much. Who knows? I certainly don't. When I hear about things like this, I just file them away as interesting little factoids, because I know I can't explain it.

Sorry if I sounded pretentions or wrote too much or whatever. I just thought I might be able to join in on an interesting conversation and maybe help answer a few questions.

so i'm caucasian and my mother is a redhead (i turned out a brunette), so then is it possible if i marry someone who is part asian with a gene for red hair that we could have children part asian with red hair?

Nadia, thanks for your post. It was interesting.

the family must have the ressive genes for blue eye and blond hair or maybe the have some ancestor with those features like thier whole maybe isnt pure japanese

Yes, Jen, the children could be part Asian with red hair but as they would only be a quarter Asian or less they wouldn't look very Asian at all, they would most likely be seen as Caucasians.

I know a couple of people who are quarter Japanese- you would never guess it. I also know a few people who are 3 quarters Japanese (American grandfather) and you can perhaps slightly see the Caucasian influence if you look carefully but really they look Japanese.

There is no such thing as pure or all Japanese. The Japanese are a mixture of groups, thus you see blue eyes, and auburn, light brown haircolor, as well as various other coloring. Some babies have blonde streaked hair or blonde to light brown/auburn hair. My grandmother has blue eyes, mine are light brown, my relatives have the same. My eyes are getting lighter with yellow spots. I'm thinking they may turn blue like my grannys.

i study some of this in anthropology... two blue eyed parents can have a brown eyed offspring and visa-versa... as well was 2 brown to have blue eyed offspring... its not like all ur ancestors had blue eyes and somehow u ended up with a brown-eyed child, that would be incredibly unique and impossible. there is a variation of genes in a line of family. and genes are always able to mutate, but only slowly over time. i am half asian and half caucasion. and ended up with white skin and brown/red hair.. perhaps the darker colors aren't always dominate as we expect them to be.