Blue-eyed humans have a single, common ancestor
What Is The Genetic Mutation
"At first, we all had brown eyes," stated Professor Hans Eiberg from the branch of mobile and Molecular remedy. "however a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the introduction of a "switch," which literally "became off" the capability to produce brown eyes." The OCA2 gene codes for the so-known as P protein, which is worried in the production of melanin, the pigment that offers shade to our hair, eyes and pores and skin. The "transfer," that is positioned in the gene adjacent to OCA2 does not, but, flip off the gene completely, however instead limits its movement to lowering the production of melanin within the iris -- successfully "diluting" brown eyes to blue. The switch's impact on OCA2 is very unique therefore. If the OCA2 gene had been absolutely destroyed or grew to become off, human beings might be with out melanin in their hair, eyes or skin color -- a condition called albinism.
Limited Genetic Variation
version in the colour of the eyes from brown to inexperienced can all be defined by means of the amount of melanin inside the iris, however blue-eyed individuals simplest have a small diploma of variation in the quantity of melanin in their eyes. "From this we are able to finish that every one blue-eyed people are linked to the identical ancestor," says Professor Eiberg. "they have all inherited the identical transfer at precisely the equal spot in their DNA." Brown-eyed people, via comparison, have massive character variant in the location in their DNA that controls melanin production.
Professor Eiberg and his group tested mitochondrial DNA and in comparison the attention colour of blue-eyed people in international locations as various as Jordan, Denmark and Turkey. His findings are the modern-day in a decade of genetic studies, which started in 1996, whilst Professor Eiberg first implicated the OCA2 gene as being accountable for eye coloration.
Nature shuffles our genes
The mutation of brown eyes to blue represents neither a positive nor a negative mutation. It is one of several mutations such as hair colour, baldness, freckles and beauty spots, which neither increases nor reduces a human's chance of survival. As Professor Eiberg says, "it simply shows that nature is constantly shuffling the human genome, creating a genetic cocktail of human chromosomes and trying out different changes as it does so."
version in the colour of the eyes from brown to inexperienced can all be defined by means of the amount of melanin inside the iris, however blue-eyed individuals simplest have a small diploma of variation in the quantity of melanin in their eyes. "From this we are able to finish that every one blue-eyed people are linked to the identical ancestor," says Professor Eiberg. "they have all inherited the identical transfer at precisely the equal spot in their DNA." Brown-eyed people, via comparison, have massive character variant in the location in their DNA that controls melanin production.
Professor Eiberg and his group tested mitochondrial DNA and in comparison the attention colour of blue-eyed people in international locations as various as Jordan, Denmark and Turkey. His findings are the modern-day in a decade of genetic studies, which started in 1996, whilst Professor Eiberg first implicated the OCA2 gene as being accountable for eye coloration.
Nature shuffles our genes
The mutation of brown eyes to blue represents neither a positive nor a negative mutation. It is one of several mutations such as hair colour, baldness, freckles and beauty spots, which neither increases nor reduces a human's chance of survival. As Professor Eiberg says, "it simply shows that nature is constantly shuffling the human genome, creating a genetic cocktail of human chromosomes and trying out different changes as it does so."
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