Why green eyes are rare?
There have been THREE sets of genes identified which contribute to eye colour. The reason why green eyes are so rare is that the genes the produce green eyes are themselves rare. One set of genes has a brown and blue version, one set has a green and a blue version, and one set controls shading in brown eyes. The best explanatory theory right now actually suggests that brown is dominant to all other colours (so someone with a mix of genes is probably brown-eyed), green is dominant to blue (so a green-eyed parent and a blue-eyed one will have some green-eyed kids), and blue is completely recessive. The reason blue is more common than green as an eye colour is that there are just so few green-eyed genes in the population. It bears mention that this theory fails to explain many oddities of eye colour, so there are probably several other genes that are involved but haven’t been located yet. (That’s what makes biology exciting, if you ask me!) Nor is there any reason to believe that green ey