|MadSci Network: Genetics|
Changing hair color.... It turns out that hair color is more complex than just a single gene. Actually it is a set of genes... and the ones that are active depend on your age. In the same way that you produce growth horomones through a certain age, and then quit - thank goodness - the genes in charge of hair color shift. It turns out you may have a series of genes in charge of hair color. At one point your "young" genes are in charge - and you may be a light blonde, or a bright red-head. Over time, the horomone balance in your body changes, and your "adult" genes take over. As a result, your may become a dark blonde, or your red hair may turn auburn. In a few populations blonde is blonde is blonde... these tend to be those of the most northern Nordic descent. For what ever reason it was good for survival reasons to remain light blonde... and that trait has remained. But for most populations, for a variety of reasons, hair darkens as you age. Hope this helps... Greta
Try the links in the MadSci Library for more information on Genetics.