2006-12-20 07:15:25 · 5 answers · asked by Jaze 2 in Science & Mathematics ➔ Biology
Different coloured irises are heredity, the functional unit of heredity is the gene, and DNA is the molecule responsible for heredity. Its color is determined by the interactions of a number of complex factors. Brown eyes have brown pigment in the iris. On the other hand, blue eyes are not caused by a blue pigment but result from a scattering of light by the tissue of the iris in a fashion similar to the scattering of light as it passes through the atmosphere or water to form the blue skies and blue oceans.
2006-12-20 08:08:28 · answer #1 · answered by Anonymous · 0⤊ 0⤋
It is not fully understood. But here's the basics...
There are three colored layers in the iris. The deepest layer is dark. The middle layer is typically a light blue colour and the outermost is a dark brown color. Whether you have any pigment in the outermost layer is determined by your genetics. If you do you generally have brown/green eyes. If you don't you have blue eyes. The difference in shades in each is due to more subtle genetic differences.
2006-12-20 16:45:56 · answer #2 · answered by Anonymous · 0⤊ 0⤋
iris coloyr is 1 of the many heredity traits controlled by genes so different people have different colours owing to the modifications in their genes due to recombination and crossing over
2006-12-20 15:21:47 · answer #3 · answered by Abhinav 2 · 0⤊ 0⤋
Same reason as they have different colours of hair or skin... different pigmentation, caused by different genes.
2006-12-20 15:18:32 · answer #4 · answered by computerguy103 6 · 0⤊ 0⤋
its all to do with your genes
2006-12-20 15:24:55 · answer #5 · answered by Smiley_1714 5 · 0⤊ 0⤋