Hair and Skin Color Genetics (can one visibly determine paternity)

Maybe this is better for a short term topic, but it could very well get complex and long so I am putting it here. Recently an issue came up in a family I know and since I do not know enough about genetics (specifically hair and skin color) I want to ask the experts here.Is it possible to determine paternity based on hair and skin color? Now I am not talking about the obvious two extremely white, blond-haired blue-eyed people having a black kid. At least I think that would be obvious.In this case a father had red hair and light skin, while the mother had blonde hair and light skin. The children both had dark black hair and darkish skin (not black but brown compared to the pale white skin of the parents). Is that possible?Inquiring gossips would like to know.This message has been edited by holmes, 03-26-2005 12:10 PM

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)

I can't answer the question at all...but I did want to guess...that it IS possible.I hope that the issue is not causing the family undue stress, if people are thinking what you're implying...or worse, the husband is thinking it.

It's a matter of recessive and dominant genes and links between them and the muddy waters of genetics when a variety of results is possible (ie -- probably involves more than one gene)red hair is usually linked to very fair skin of the Woody Allen "I don't tan, I stroke" variety. and this also holds to a lesser degree with blond hair (there is a higher preponderance of fair skin with fair hair than without)BUT I don't think there is any real {recessive\domininant} pattern to hair color: look at couples that have "mixed" marriages {(black\blond),(brown\blond),(red\brown), etc}, and at the hair color of their children -- there is usually a mix.that being said it is entirely possible for the child to get genes from both parents that are suppressed in the parents but here let free.My dad's skin is darker than his parents, and darker than any of us kids. His hair is also dark and curly and he has brown eyes, yet one child has brown eyes, two with blue, two with lite brown, one with straight hair (doggone it).Is there any pattern in the rest of the family for dark hair and darker skin?{added by edit}I also tan easily, which may be part of the skin tone issue.ps -- at first I thought this was going to re-open the skin bareness sexual selection issue ... This message has been edited by RAZD, 03*26*2005 01:24 PM

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

Yeah, I was hoping to attract someone that might know about the dom/rec traits of hair and skin and be able to work out some sort of mendelian chart on this.Me and my gf were of the assumption that both red and blonde were recessive and required to be homozygotic (?), otherwise you get whatever other color there is a gene for (not sure how they stack against each other).Thus it seemed to us (and the others that started this whole question going) that it would be impossible for a red head and blonde to have darkhaired kids.I thought skin color might be a lot less likely of a clue than hair... but figured I should drop that in.Will have to check on family history.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)

My father has wavy dark blonde hair and gray eyes, and my mother has straight jet black hair and brown eyes.I have wavy dark brown hair and hazel eyes.My brother has medium brown wavy hair and brown eyes.One sister has medium brown straight hair and brown eyes.Another sister has straight dark blonde hair and blue eyes.All of us have pale skin so I didn't include that.I would ask what the parents and grandparents of these folks looked like.

because there are so many variations in hair color I doubt it is a single gene sequence.think of this possibility: each is recessive but on a different stretch of the chromosome, the redhead carries a sequence that counters the blonde and the blonde carries a sequence that counters the red.then you have a possibility that one is really dark hair dark skin genetically, but the expression of the genes were suppressed during development (in the manner that failure to generate testosterone at a critical stage can result in an outward female but a genetic male)but yeah, where are the geneticists when you need them ....

I think it would be especially difficult when dealing with children.Both of my parents as well as all four Grandparents had dark hair. All had brown eyes.When I was little I had reddish bronze hair. Gradually it turned dark and by the time I was six or so it was near black.I have hazel eyes.I have one sister that is a blonde.All the other six gizzillion siblings were born with dark hair and brown eyes.Two brothers were bald by their thirties.

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Aslan is not a Tame Lion

Hi, this is a general reply.The genetic basis of skin and hair colour is not very well understood. Skin color largely depends on the structure of melanins in the skin cell, while hair color largely depends on the structure of melanins in the hair follicle. Melanin is a very complex polymer that consists of an unknown number of protein subunits, each of which is presumably coded for by at least one gene. The fact that we haven't actually isolated many of the subunits of melanin means that we don't have a clear picture of how phenotypes are inherited. There is no evidence that blond hair or red hair is in any straightforward way recessive.Black and brown melanin is the "standard" kind of melanin that can be found across many different species in nature. Many species also incorporate cyteine into melanin, which gives it a yellow or red color. The colour of skin itself depends not only the the structure of melanin but also on the effect of light scattering in the skin cell itself, on the amount of blood close to the skin surface (which makes skin have a kind of red glow) and on the amount of dietary carotenoid (which makes skin have a yellow sheen).It's very clear that coloration is strongly influenced by the environment. Your hair probably goes a bit blond in the summer, for example, and while your face might be the standard caucasian/brown-haired kind of skin colour, your buttocks are probably similar to the skin colour of a blond.It's also influenced by many different loci. There is a single mutation in the MC1R gene that makes red setters (the dogs) red. But this exact mutation in labradors makes hair colour turn quite yellow. It also makes yellow mice. In humans mutations in MC1R are associated with both blond and red hair. Whether it turns blond or red probably depends on the overall amount of cyteine in the melanin polymer. Given what we know about the complexity of the genetics of coloration, and complexity of its regulation in living organisms, we expect interactions between loci to make it difficult to map specific alleles onto specific phenotypes. There isn't a single "blond allele" or a "red allele".The simple answer to the question of whether we can visually ascertain paternity based on coloration, is no.Mick

I understood the basics of what goes in to coloring hair and skin from a chemical constituent angle, just not the genetic factors which would shape it.It looks like me and my gf (as well as others) had a very simplified view of the genetics surrounding the issue. Thanks for the info.

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)

thank you. now about that "gay" gene .... (just kidding )

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

I guess with the more wide-spread use of DNA tests of paternity in divorce, and the number of surprises therein, we might see one expression disappear---'He looks just like his father'.

I cannot cite, but about 10 years ago I read an article, properly researched, of an experiment conducted in maternity wards,and the general conclusion was that there was no discernable ability for parents to identify their own child.

I think I recall the same article. The problem is that they're all bright pink, and screaming, and look like Winston Churchill.