h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Gaily ripping off a post or two in the 'why is everybody irish' thread and a few comments on red hair there and its geographical locations I thought I'd ask a further question.

Why? Why Red hair?

Black / Brown and Blond fair enough i guess (or maybe I am wrong) but red hair seems to be a bit of an oddity (sorry, not saying the people are) and I was wondering what survival benefit it may now, or in the past, have conferred?

Or is it just a piggyback mutation which does not have enough of an effect to cause either a negative or positive impact on the survival of the individual?

Is it linked to other things and are any of the traditional things really associated? I.e. temper, fair skin.

Oh, and were they put on the earth by aliens as claimed by some

Bookmarking and ready to add names to my little black book of who's first against the wall come the revolution

Blimey that was quick! Practically a simulpost on the first post!

So you are then I take it? Any insights to add?

Oh, and i forgot to add above, if red, why not blue, green, purple etc.?

myth and rumour and my forgetful brain tells me that red hair used to be as common as brown/black/blonde hair but that the romans thought it was related to witchcraft/bad luck and so people with red hair were either killed or were pretty much shunned by society and not allowed to breed, so everywhere the romans took hold red hair genes all but disappeared...which is why red hair is still fairly common in scotland and ireland but not the rest of europe. And I suppose this rarity is why some people see it as an easy target

I think red hair and the associated sensitivity to sunshine are a disadvantage everywhere the sun ever shines, which is why it's common in Scotland and Ireland.

The only genetic advantage I've seen claimed for it is that Vitamin D is made in the skin and some UV is needed. In climates with very little sun, pale skin may allow the UV needed through better than darker skin, and the very pale colour that usually comes with red hair may be selected.

I don't know if the positive effect is real, but the negative effect of red hair and pale skin in sunnier climes certainly is.

Hed

Hmm, after looking at a few websites... apparently I've inherited a genetic mutation...



Anyone know where I sign up as an extra for the next X-men film

Anyone know where it stands in the hierarchy of things?
What I mean is, things like the blue / brown eyes i seem to remember that the brown is dominant so if you get one of each then you will have brown eyes. Or something.
Do both your parents have to be red heads for you to be? Is it dominant over others or just random?

Whisky, have you found a tendancy for your eyes to turn blood red and smoulder or anything like that?

*puts on white coat for a bit in an attempt to sound like she knows summat - but quite obviously doesn't*

Hair and eye colour are not determined by one single factor but a plethora of them. So we can't say that red hair is a 'mutation' as such, but that the combination of factors that results in red hair is not prevelent in most cultures.....excepting Scotland and Ireland obviously. Which means that something in those other cultures (read Romans) has worked against that colour.

Blue eyes...or the factors that are required to form 'blue' eyes are more rcessive thatn brown eyes, but that does not mean to say that two blue eyed people cannot produce a brow/green eyed child...it's just unlikely and dependant upon what of the various factors the child inherits.

The fact that certain hair and eye colours go together is probably more to do with genetic background than the fact that their determinant genes are 'linked'.

Urmm...lost myself here. I maycome back..

*takes off white coat and goes back to doing some genetics... <

Zantic

The gene for red hair is dominant..very dominant
You only need one parent to have it.

And yes we usually do have fair skin and fiery tempers! I doubt Im an alien or was put here by them.. but I am a witch!

You only need one parent? Does the father lay an egg?

If red hair was as dominant as all that, it'd be all over Europe and North America. The fact that it's still the rarest color centuries after the Romans shows how recessive it is.

My mother-in-law's mother had red hair. The mother-in-law's is black. My wife inherited her mother's recessive red gene, because she sports red highlights. But her predominant hair color is black, like her father's.

It's definitely not very straightforward. There is no one in my family (that we've been able to track down at least) on either side for three generations with red hair, yet out of my parent's four children, both my sisters have bright red hair. Assuming it wasn't the milkman, as we so often joke, where did the red hair come from???

I meant to say one parent ..with it am all over the place today!

Napnod: If both your parents were carrying a recessive red gene, then their offspring would have a 25% chance of having red hair. It sounds like they beat the odds.

I'm quite likely carrying a recessive blonde gene (among the indicators, the middle of my mustache grows in blonde, which looks very weird and is another reason I'm clean-shaven), and I don't really know where it came from. My mother was blonde as a child, and her hair gradually darkened to a deep brown. Nobody in the family apart from her ever exhibited blonde hair.

If the gene is recessive, it can be passed down several generations before it gets a chance to manifest itself again.

I shall have to let them now. I also used to have blonde hair when I was a child that darkened to dark brown. Does this mean I'm more likely to have a recessive blonde gene rather than a red on?

Well, whatever the reasons, can i just say that i, and most of my male (and some female) friends think that red haired females are absolutely stunning .. Very rarely see an unnattractive one , so i surmise that the genes for red hair and beauty are linked

The whole recessive thing is definitely true - ginger tends to be a recessive gene - and i have a friend who is a redhead, but no one had had it for four generations...

Its very difficult to get a red head - everyone has two genes for characteristics like hair colour, normally a dominant (written in CAPITALS eg R) and a recessive (written in lower case eg r)
- if you chart someone with blonde hair dominant (B) and red hair recessive (r), who pairs up with someone with brown hair dominant (BR) and red hair recessive (r) - their kids could be
B r (blonde)
B r (blonde)
BR r (brown)
BR r (brown) etc etc
or very rarely rr (red)

So that's why their so rare - they are supposed to be from ireland and from scotland.

I dye my hair red...

Ahem.

I also dye my hair.. only a darker shade of red though.I was ginger till I ws about 5 ,then it turned over the years to a gorgoeous shade of strawberry blonde ..but i wasnt happy with it ,wanted more of a mahogany (which mum now tells me it wouldve done on its own like her granny!)..so ive ended up dying it ever since ..its been all sorts of shades.going back to poppy tomorrow.

perhaps they get bullied so much they feel they have to compensate...

-- DoctorMO --

Listy that should be...

r r
BR r
BR B
B r

25% each.

-- DoctorMO --

oh yeah!

It's been a while...