Subject: Does the gene for red hair come from Cro-Magnoids or from Neanderthals?

There was a short article in some newspapers about the 'gene for red hair'.
 It said that it is quite old and maybe Western European populations adopted it
 by admixture of the Neanderthals which were thought before not to have 
contributed
 to the gene pool of modern European populations. 
 Unfotunately I forgot the name of the scientists who did the research and 
couldn't find any information about that in the web.
 So my questions: which gene do they talk about? how did they calculate the age?
 Why Neanderthals and not Cro-Magnoids? Do really only Caucasian people have red 
hair or are there also some rare cases in other races? What about the redhaired 
mummies in Egypt and South America, which race do they belong to? Is their hair 
naturally red or reddish blond or was its colour changed by some chemical 
reactions?
 

Re: Does the gene for red hair come from Cro-Magnoids or from Neanderthals?