Monday, March 08, 2010

The redhead gene

Ten years ago, as an undergraduate biology student, I wrote a research paper on MC1R, a gene that helps control hair and skin color. Certain mutations of MC1R cause very pale skin and red hair. In my paper I wrote that it's advantageous to have that combination if you live in northern climes, because your skin needs sunlight exposure to produce Vitamin D, and there's so little sun up north that it's better to have translucent skin to let as much sunlight through as possible. Nearer the equator, there's no worry about getting enough sun (unless you're a woman who keeps all her skin covered for cultural reasons-- such women do sometimes suffer from rickets, a disease caused by lack of Vitamin D.) But there is worry about skin cancer where the sun is bright, so at the lower latitudes it's better to have very dark skin.

None of this was original thinking; it was the conventional thinking which I lifted from the papers I read in the course of my research. And now some other student has written a paper on a similar topic and has offered the same standard theory, which isn't surprising at all. What is surprising is that the Telegraph seems to think that it's news!

Whatever. Here's a fun fact: the MC1R gene that causes red hair in humans is also responsible for similar coat colors in rats, dogs, and the glorious Highland cow.

5 comments:

suek said...

Arrived by way of First Things. My genetic education was a long ago thing, but has fascinated me since then. Having had red hair as a child, and a M_I_L who kept telling me that she wanted a red-headed grandchild - which I didn't provide! - that particular topic has also been of interest to me.

As a matter of observation, I've divided redheads into two categories - German redheads, and Irish redheads. Irish redheads are those we normally think of - red hair, very white skin, freckles. They sunburn easily. (that's me, by the way) German redheads, on the other hand, tend to have skin that tends to be tawny, they tan easily - outrageously easily, in fact - and they don't have freckles. Irish redheads usually have blue eyes, German redheads have brown eyes.

In horses - which I have raised - the chestnut coloration is a recessive. I suspect that the same hair coloration in humans is recessive as well - but I'm not aware of any research done on it.

By the way...if you're serious about having a vocation, I have experience with two orders, although my experience at this point is pretty out of date. My sister is a Sister of Charity of St.Vincent de Paul, a teaching order with a motherhouse in Maryland. I'd be happy to supply you with her email address if you'd like a personal contact. The order I was taught by in high school was the Ursulines of Brown County http://www.ursulinesofbc.org/

If you do a search on "Brown County Ursulines", you'll come up with some interesting stuff. When I went there, it was a boarding school. These days, they have a private college - 2 yr, I think - and primarily nursing.

Rachel Gray said...

Thanks Suek!

My own mom used to encourage me towards men with redhead genes. :) The two types of redheads thing is interesting, because one of the papers I read ten years ago said that red hair had been assumed to be a recessive trait (as it is in animals), but there was a Danish population in which it seemed to be dominant. There were plenty of unanswered questions about it all; I'm sure more research has been done since then.

suek said...

>>I'm sure more research has been done since then.>>

Well...it isn't exactly a critical issue! On the other hand, students working towards Masters and Phds have to have _something_ to work on!

Re the Danish population/dominant thing. If you think about it, within a relatively closed population recessive characteristics could seem to be dominant if the characteristic is so widely carried within the population that any two seemingly random individuals might carry it as a recessive, and it could easily pop up when one parent has the characteristic and the other doesn't appear to. That would be pretty easy to check on though, by simply determining if any of the redheads had both non-redhead parents. It's always interesting, isn't it! Working with human populations has to be more difficult than with animal populations - you can't exactly plan an experimental breeding program to test theories!

Warren said...

You were expecting a scientifically literate and well-educated journalist? Now THAT would be news-worthy. Because though they do exist, they are rare, outside the science magazines and academic journals.

Heck. Scientifically literate people are rare at Academic journals these days. I love those "bogus studies" that people submit to see if journal editors and referees will catch them, or not. Usually one can float just about any content-free boat one wants to float, in theoretical physics, and in a few other places too, where frankly, not even the experts in a field can explain what the heck the other experts are talking about.

W

Rachel Gray said...

You're right about working with human populations, Suek! I think research into this stuff is quite interesting. One tidbit I found, for example, is that hair samples can be tested for illegal drug use, which shows up in the hair months after the use. But it was determined that this was an unfair test, because dark hair colors retain the drug more, while blonds and redheads can get off scot free!

And Warren, you're even more right that the standard journalism degree doesn't include the ability to understand and convey all the scientific research... It must be hard in a way to be a journalist, because unless you specialize as a fashion writer or something, almost anything you write about is something on which you're no expert.

I've heard of some of those bogus studies. GREAT stuff. On a similar note, there was a white Englishman who got a book of short stories published by pretending to be a woman of Arabian extraction.