Vrlo interesantna teorija. To bi značio sljedeće: da ni roditelji ne uvjetuju boju očiju svojeg djeteta, niti čiji su kromosomi jači, već je to jednostavno igra majke prirode. Možda mi svi nosimo gen plavookih, ali taj gen mutira i rađamo se različitih boja očiju. Čitala sam npr. da prirodne plavuše (i muške i ženske osobe) sa plavim očima izumiru kao vrsta.
Blue eyes contain low amounts of melanin within the iris stroma; longer wavelengths of light tend to be absorbed by the underlying iris pigment epithelium and shorter wavelengths are reflected and undergo Rayleigh scattering. The type of melanin present is eumelanin. The inheritance pattern followed by blue eyes is considered similar to that of a recessive trait.Eiberg and colleagues showed in a study published in Human Genetics that a mutation in the second intron of the HERC2 gene, which is hypothesized to interact with the OCA2 gene promoter, reduced expression of OCA2 with subsequent reduction in melanin production. The authors concluded that the mutation arose in a single individual around the Black Sea region 6-10,000 years ago.
Blue eyes are relatively common throughout Europe and occur randomly in other areas with populations of Indo-European descent, such as Iran and India. In India, it is not unheard of for parents with brown eyes on both sides to occasionally have blue-eyed children.
Blue eyes are mostly common throughout northern and Eastern Europe, especially in Finland, Sweden, Iceland, Norway, Denmark, Germany, Russia and Poland (blue or green eyes are charactered for slavonic ethnic groups). One survey estimated that nearly 90% of Icelanders have blue or green eyes, while another reported 50-80%, in contrast to 20%-49% of Spaniards and Italians of the north. A 2002 study found the prevalence of blue eye color among whites in the United States to be 33.8% for those born between 1936 and 1951 compared to 57.4% for those born between 1899 and 1905.
As melanin production generally increases during the first few years of life (especially if exposed to the sun), the blue eyes of some babies may darken as they get older.