The Straight Dope

Go Back   Straight Dope Message Board > Main > General Questions

Reply
 
Thread Tools Display Modes
  #1  
Old 01-21-2006, 04:59 PM
monstro monstro is offline
Guest
 
Join Date: Mar 2002
What would cause multi-textured hair (genetics related)?

I have a mosaic of hair types on my head. I have furry hair on the left side of my head. On the right side, the hair is full of loose and medium-loose ringlets. The very front of my hair, where bangs would be, is wavy, almost straight, as is the hair around my ears on both sides of my head.

The hair on the back of my head is 100% bushy and kinky, except for the areas that extend from the sides. Those areas are 1) furry on the left and 2) wavy/curly on the right. A pronounced region of African bush separates the two.

The hair at my nape is wavy fur.

The question is why? What, developmentally, causes such a pattern? It can't be solely genetic, since the hair follicles all the carry the same genes. They're obviously expressing those genes differently, but how?

Or am I wrong in assuming that all the hair follicles on the head carry the same genes? Hair texture, as far as I know, is not a sex-linked trait. But couldn't some of the hair texture phenotype be influenced by genes on the X-chromosome? Is my hair a mosaic because I've got the whole "calico cat" thing going on? My parents do have striking differences in hair texure. My father has fine, wavy hair. My mother has "straight from the Motherland" hair. (Both are black Americans, btw).

I'm sure my hypothesis is wrong, but I can't think of any alternatives. Can anyone drop some Doper knowledge on me?
Reply With Quote
Advertisements  
  #2  
Old 01-21-2006, 05:29 PM
Blake Blake is offline
Member
 
Join Date: Mar 2001
Posts: 10,207
This is one of those things thatís going to be impossible to answer, not least of which because the genetics of hair texture, like most things, isnít well understood.

First off is the mundane. People have different hair textures normally. Not only that but it changes throughout their lives. Itís not all that uncommon for people to have wavy or even curly hair as children that straightens out with age, and I know of at least one case where straight hair went wavy with age. Itís also not uncommon for men to have sideburns that blend into wavy hair and then straight hair. So the fact that your hair comes in a few different textures may be completely meaningless.

Next the unusual. Iím assuming you are female, and if so you may be experiencing the effect of female mosaicism. I have no idea if hair texture is influenced by the X chromosome, but since hair we know that hair colour, thickness and growth are all influenced by the Y chromosome it hardly seems implausible.

And finally the outright bizarre. You may be a chimaera. A lot of people are. In essence a person is formed form the fusion of two non-identical twins. As a result the body is composed of a patchwork of cells form each sister genotype. Iím not sure what the scale is for chimaera mosaics, but since most of what you describe seems to be a left-right difference itís plausible.
Reply With Quote
  #3  
Old 01-21-2006, 05:36 PM
Colibri Colibri is offline
SD Curator of Critters
Moderator
 
Join Date: Oct 2000
Location: Panama
Posts: 25,798
Since Blake has already covered most of the points I would have mentioned, I'll just offer this link on human hair texture, which also mentions that the genetics is not well known.
Reply With Quote
Reply



Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 12:52 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.

Send questions for Cecil Adams to: cecil@chicagoreader.com

Send comments about this website to: webmaster@straightdope.com

Terms of Use / Privacy Policy

Advertise on the Straight Dope!
(Your direct line to thousands of the smartest, hippest people on the planet, plus a few total dipsticks.)

Publishers - interested in subscribing to the Straight Dope?
Write to: sdsubscriptions@chicagoreader.com.

Copyright © 2013 Sun-Times Media, LLC.