Sorry if this has been already asked, but I’ve searched the archives and only seen Cecil dodge the question. Where does red hair come from, and why did it survive natural selection? It certainly isn’t helping me “pass on my genes.”
I hear you buddy, so guys like us just have to concentrate on making a shit-load of money;)
I have red hair, or at least I used to, and I think it is just an exaggerated phase of brown hair. At least many red heads hair turns sort of brown as they get older.
And why should it be selected against? What is the disadvantage?
Red hair is just part of the continuum of colors possible. Hair color, like skin tone and height, is determined by a big honkin’ group of genes, so it’s not quite as simple as the Bb brown/blond scenario. When you have multiple genes being expressed for the same triait, you often wind up with something in the middle. Dave’s right up to a point, red hair is a variant of brown/black hair. The expression of those genes is just being tempered by the simiultaneous expression of light-hair genes. That’s also why dark-haired people often have reddish or blond highlights in their hair.
As far as natural selection goes, hair color is generally a pretty neutral character. That means there’s no selective pressure for or against it, so new variants tend to persist. If redheads couldn’t find mates, or tended to die in childhood or something, then the trait would be more likely to die out. Not everything evolves in response to being selected for. Sometimes traits arise simply because nothing’s selecting against them.
Sounds like the disadvantage is he can’t get laid.
Red hair, like the other colors, is just a product of the pigments. As I understand it, there are two types of the pigment melanin: eumelanins and pheomelanins. Brown and black hair tends to have more of the darker eumelanin. Red hair has more of the pheomelanin. This article seems to have a good explanation of the basics.
Fun fact: melanin is the same pigment that colors the skin. Since redheads tend to have less of the “dark” pigment, the pale skin and freckles are often associated with redheaded-ness.
I seem to remember there was some discussion on these boards about whether the genes for red hair come from neanderthals. However, I’m not sure there is any conclusive evidence that neanderthals and humans ever interbred. I’ll try to find a link to that thread.
For something to fail to “survive evolution” it doesn’t have to hurt your chances of not…ah, crap. Too many negatives - I’ve lost track. Let’s try again.
Red hair doesn’t hurt your chances of reproducing. For a trait to stick around, it doesn’t have to actively help you, it just has to not actively hurt you. If it’s neutral, like red hair, there’s no mechanism out there to eliminate it, except random chance.
Not mine. I’ll be 43 this year and my hair is still bright red, almost orange. Not a speck of grey either. Except in my beard. I have grey starting to pepper my otherwise fire engine whiskers (I’m Red Beard the Pirate donchaknow:p )
And who’s to say it doesn’t work as an advantage in this regard?
Some traits are passed on despite having no apparent survival advantages or disadvantages because they give a sexual advantage. Anything that makes you stand out in the crowd.
My hair is still red, but unlike pkbite’s, mine seems to get blonder with the years :).
My great-grandmother, who was Italian, had red hair, married a brunette, the red didn’t show up again until my generation. 5 of the 10 of us are redheads. It’s never been a disadvantage for me except in Scotland. I was meeting someone I didn’t know & described myself as a redhead. “That’s not good enough, lassie, too many of you around here.”
I’m a redhead. It was kind of strawberry blonde when I was a child and is more light auburn now. I’ve never considered it a disadvantage at all - at least not after I got out of elementary school. And it definitely never made me feel unattractive, as a matter of fact I think it helped me get laid. 
Oh and my last boyfriend had red hair too so maybe it isn’t hair color.
But as far as genetics, I have two brown haired children, one dark and one light and a blonde - no red in the pool.
mipiace is too right.
I have 5 brunette children.
LeprechaunPaul – are you fair & freckled too? If not, & you truly think your hair is responsible for your chastity, why not go brunette? Also, lots of blondes are fair & freckled.
Fuzzy memory of reading about a redhead called a “sport” – trait that pops up out of nowhere. Think it said this is an American thing. Anybody?
I think that is it incredibly unfair that my 2 brothers and at least 8 of my first cousins have redhair naturally and all I got was brownish-auburn hair … thank heavens for my hairstylist (I know exactly where my redhair comes from!)
I have red hair and get more ass than a toilet seat. A lot of the women I’ve been with say they like it. Maybe this guy’s just a loser and that’s why he can’t get any. It’s a poor musician who blames his instrument, remember.
Well it looks like Chunky is going to fit right in here. :rolleyes: Perhaps you should read the forum descriptions.
Anyhow - red hair is a naturally occuring genetic annomoly, as are green eyes.
It will never be bread out, so to speak, because it occurs as a natural genetic blip in about 5% of the population.
I also seem to recal that it’s dominant - meaning if you have a red head in your family, you’ll probably have more than one.
We travel in packs! 
FWIW, my mom is red and I’m red. My brother is brown, but his beard is red and his eyes are green.
My dad is just plain old brown and brown. 
Haven’t any of you people read Still Life With Woodpecker? Don’t you know that redheads are decendants of an alien race?
Fellow redhead,
NailBunny
Maybe you’re a guy. 'Cuz I am drawn to the redheaded ladies like an Electro-Magnet.
Thank you, oh supreme-being in the sky for redheads.
Any mathematical geneticists around here? What would be the effect of a gene that is detrimental to survival/reproduction when expressed in a male, but has a positive effect when expressed in a female? How about vice-versa?
(Odd but true: I have never dated a blonde. I have dated a number of brunettes, but never slept with any. I have dated three redheads, and slept with all of them. {Not all at once. Perverts. } So the question is, does this say something about blondes, brunettes, and redheads, or about me?)
Freckles are not inevitable in redheads. Freckles are a sign of sun damage. If you never expose your butt to the sun, you don’t get freckles there, and that’s why your face and arms have more freckles than the rest of your body.
I once saw a small toddler with brilliant bright hair, she had the most beautiful skin and rosy cheeks, and not a single freckle. That’s when the above realization hit me. You could say european redheads have the least pigment of all humans, even less than light skinned blondes.
Now what I’m really wondering, is if the redheads that appear among the australian aborigines have the same pigment governing gene as Europeans with red hair. In Europeans, it is always linked to skin color. Obviously in australians it is not. Why is that?
IANA population geneticist…but I would think that secondary sex traits would be selected for more strongly in the sex that competed more for mates. In other words, if there weren’t a lot of men out there, and the women had to compete for them, it would be advantageous for women to have red hair even if some of their male offspring were less attractive. Since it seems, though, that in most human societies men have to compete more for mates than women do, than I’d wager it’d be more advantageous to develop a trait that increased male attractiveness at the cost of reduced female attractiveness. Or, to put it stereotypically: women can always get some action;)