... well, this is how brown eyes are made blue:
Matt Ridley explains, while we are influenced by our genes, dependence works the other way around,too. Genes are vitally influenced by man and his culture.
Human beings, we tend to think, are at the mercy of their genes. You either have blue eyes or you do not (barring contact lenses); no amount of therapy can change it. But genes are at the mercy of us, too. From minute to minute, they switch on and off (i.e., are actively used as recipes to make proteins) in the brain, the immune system or the skin in response to experience. Sunbathing, for example, triggers the expression of genes for the pigment melanin.
As a recent study confirms, on a much longer time scale, genes are even at the mercy of culture.
Make sure to read the entire article at the source.
