How is eye color determined

Countless students have been taught that a single gene controls eye color, with the allele for brown eyes being dominant over blue. Scientists now realize such a model is overly simplistic and incorrect. Introduction In , Charles and Gertrude Davenport developed a model for the genetics of eye color.

They suggested that brown eye color is always dominant over blue eye color. This would mean that two blue-eyed parents would always produce blue-eyed children, never ones with brown eyes. For most of the past years, this version of eye color genetics has been taught in classrooms around the world. Unfortunately, this model is overly simplistic and incorrect — eye color is actually controlled by several genes.

Additionally, many of the genes involved in eye color also influence skin and hair tones. A primer on pigmentation The color of human eyes, skin and hair is primarily controlled by the amount and type of a pigment called melanin.

But modern science has shown that eye color is not that simple. Eye color isn't just a blend of the parents' eye colors, as in mixing paint. Each parent has two pairs of genes on each chromosome, and multiple possibilities exist for how this genetic information is expressed in terms of eye color. The influences from each parent on eye color aren't fully known until after the child is born and begins to mature.

Brown is the most common eye color worldwide. There are many shades of brown eye color. Also, the prevalence of eye colors varies geographically. Most people in Africa and Asia have dark brown eyes. Even hazel eye color is sometimes considered a shade of brown eyes. Green is considered to be the rarest naturally-occuring eye colors. Some surveys suggest green eyes also are considered the most attractive eyen color.

J Hum Genet. Epub Oct Other chapters in Help Me Understand Genetics. Genetics Home Reference has merged with MedlinePlus. Learn more. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.

Is eye color determined by genetics? From Genetics Home Reference. Topics in the Genetics and Human Traits chapter Are fingerprints determined by genetics? Is intelligence determined by genetics?

Is handedness determined by genetics? Is the probability of having twins determined by genetics? Is hair texture determined by genetics? The color combinations in shades of green, brown, and gold are endless with hazel eyes, depending on the concentration of melanin. The light scatters as it does with blue and green eyes. As with blue and green eyes, hazel eyes may appear to shift colors depending on the light. It is unknown if hazel eyes developed from brown eyes or green.

Your eye health may significantly impact your everyday life, from socializing with friends to driving at night. Get started here. Is Eye Color Genetic? June 3, October 8, Learn more about the genetics of eye color, including: How is Eye Color Determined?

Is Eye Color Inherited? Can Eye Color Be Predicted? How Is Eye Color Determined? Brown Eyes The majority of people in the world have brown eyes. Blue Eyes Originally, all humans had brown eyes. Hazel Eyes Hazel eyes are sometimes mistaken for green or brown eyes. How does your eye health impact your life? Tags: eye eye-color genetics genomes. This website uses cookies to improve your experience. Visit our privacy policy to learn more. Close Privacy Overview This website uses cookies to improve your experience while you navigate through the website.

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