Eye colour: a brief history of genetics

Eye color is determined genetically. But how are there so many shadows? Can we predict the color of our children’s eyes?

The important role of melanin

First of all, you should know that the color of the eyes, like the color of our skin or hair, is determined by the amount of a molecule called melanin. in bright eyesLess melanin is stored in the iris. From a genetic point of view, we often learn that it is a dominant allele, or a copy of the gene responsible for brown colour. On the other hand, it is a recessive allele that is responsible for the blue colour. If the dominant and recessive aspect of these colors is true, then things will be more complicated for genes. In fact, it is not a single gene that determines eye color…more 150 gen Its effect has been determined!

Read also: Where do blue eyes come from?

Eye color genes

Both of these genes are not of equal importance. There are two genes that appear to be the main determinants of eye color: EYCL1 and EYCL3. Each of these genes has alleles for blue, green, and brown eyes. And as we know, the brown alleles are dominant over the blue and green alleles. What is less known is that green alleles are also dominant over blue alleles! The theory that blue eyes are on the way out doesn’t hold up. Alleles do not disappear and remain transmitted. The green and brown alleles can simply “hide” them. This also means that the color can reappear, even if neither parent has blue eyes.

The influence of many other genes plays a role in other shades, such as blue or green eyes. Finally, there may also be mutations that cause idiosyncrasies, such as heterochromia, also called single eyes.